Brakes dragging and bad brake fluid

[BeetleDragon737]

Hello all,

My fuel economy had dropped off pretty dramatically over the past couple months, and brakes were my first step in diagnosis. It appears that all my brakes are dragging a little. Wheels don't rotate freely when on jacks and rotors are hot after a drive. My pads are wearing evenly though. Also, the parking brake disengages all the way.

I'm sorta new to maintenance, so I didn't realize flushing the brake fluid was something that should be done often. I bled one brake about 1.5 years ago, and the fluid was somewhere between black and dark green. Time constraints prevented me from doing the rest at the time, and I just forgot about it.

What has potentially been damaged? Would just flushing the fluid accomplish anything at this point? Should I just go ahead and replace the brake lines and all my calipers due to likely corrosion of the pistons? Is there any way to check whether I've messed up the ABS? The fluid in my brake reservoir is clear & green.

Also, turning the front wheels turns gears in the transmission too - how freely should the front wheels spin?

Thanks for any help.

 

[pj_diesel]

Sometimes the pins that the calipers ride on lose all their grease and start to stick, which make the brakes seize. That's something to check before doing anything major.

Flushing the brake fluid is something that should be done, but I haven't done it unless I'm opening up the system for a different reason. I suppose it's possible that multiple calipers are going bad at the same time, but to me it seems unlikely.

If the car is in gear, the front wheels are attached to the transmission. Put it in neutral and spin them. They're still turning the driveshafts, so they won't spin as freely as the rears should.

 

[BeetleDragon737]

Sometimes the pins that the calipers ride on lose all their grease and start to stick, which make the brakes seize. That's something to check before doing anything major.

I read that the pins sticking would give uneven wear, but I'm not experiencing that issue.

If the car is in gear, the front wheels are attached to the transmission. Put it in neutral and spin them. They're still turning the driveshafts, so they won't spin as freely as the rears should.

They should still freewheel then? Just slowing down faster than the rear wheels?

 

[csstevej]

No need to replace brake lines or calipers unless the are not retracting into the housing.

Brake fluid should be changed once every two years with starting with the right rear first then the left rear , then right front and then the left rear......at this point if your car is a manual you should then bleed the clutch......

I would pull the pins and clean them and grease with fresh high temp grease.

If the back brakes are dragging because of the brake , the e brake has a history of corroding as it passes under the rear beam.
The online vendors here sell the upgraded fatter replacement ones and they have additional helper springs to assist the release the emergency brakes.....at an additional cost.

 

[BeetleDragon737]

No need to replace brake lines or calipers unless the are not retracting into the housing.

How would I determine if they are retracting into the housing properly?

 

[pj_diesel]

I read that the pins sticking would give uneven wear, but I'm not experiencing that issue.

It depends on how long this has been happening and how stuck the calipers are. How easily does the car roll around? In neutral, the car should roll without accelerator input on a gradual slope. You can get a sense of how tight the brakes are by seeing how much effort it needs to get moving on a slope. I once had a front caliper so bad that I could hear the rotor scrape when starting from a stop(also caused severe vibrations at highway speeds). If it's really bad you also will smell it after a drive.

 

[pj_diesel]

How would I determine if they are retracting into the housing properly?

If you remove the pads and calipers, you should be able to easily press the pistons into the housing(whatever method you want for the fronts, rears need the special rotating tool). If it's a major struggle, the caliper is probably bad.

 

[kcunniff]

On the calipers, the rears need to be screwed in, not simply pushed in like the fronts. You can use this part, or something analogous:

https://www.idparts.com/metalnerd-rear-brake-tool-mn3272-p-402.html

I have the Metalnerd part, and it works very well. Just used it three weeks ago when performing a brake service on my MKIV Golf.

Change your brake fluid, as described above, this is an important and often overlooked service item. I use the Motive Powerbleeder (https://www.motiveproducts.com/coll...eeder-kits-power-bleeders-import-bleeder-kits) to do the four calipers and clutch. Fantastic, easy, and well worth the investment. Rinse and clean with denatured alcohol, and good to go. Used it on my Golf, my wife's MX-5, and my mother-in-law's Accord Sport (need separate adapter for brake fluid reservoir). Paid for itself three times over now compared to a service shop.

 

[BeetleDragon737]

Thanks guys, that was the info I needed. I guess I just had to get dirty to properly figure out my issues.

I only got a quarter of the way through the fluid flush before I noticed a tear in the boot for my left rear caliper piston. Stupidly, I pushed the piston out all the way so I could put some RTV on the tear for a temp fix. Then I found out the piston was seized. I fought for two hours to get it back in and bent my caliper tool.

So I definitely need to replace that caliper.

As for the other calipers - after a drive, should the rotors be hot at all? And regarding brake drag, should there be none whatsoever? Or is minimal drag that just makes the rotors warm after a drive pretty normal?

 

[csstevej]

You do realize that you have to twist them while pushing the piston back in on the rears right?
With minimal drag they might get warm ...... I’ve only noticed it when they were really out and would smell them....
Plus my driveway is inclined a little, so when I leave , I release the parking brake and see if the car rolls naturally with no sticking or binding.

 

[valvecrusher]

As for the other calipers - after a drive, should the rotors be hot at all? And regarding brake drag, should there be none whatsoever? Or is minimal drag that just makes the rotors warm after a drive pretty normal?

Rotors normally build up heat, when driving, even on a brand new car....

However, it should be minimal, not like standing by a woodstove.......THAT would be too much radiating heat....perhaps caused by old fluid, or a seized/dragging caliper....
And certainly not 'glowing' visibly...that would be a serious dragging brake pad


Having old fluid in the system could be the only problem, brake fluid attracts water...water expands MUCH easier that synthetic brake fluid...at a much lower temperature..., thus will make brake pads drag as they heat up....dragging makes them heat more, it's a compounding effect..


Don't evaluate brake performance until AFTER there is a complete and total brake fluid change, getting the old contaminated with moisture stuff out




I've had lots of experience with a 'brake drag' being completely resolved with a complete 100% fluid change..

.02

 

[KrashDH]

Thanks guys, that was the info I needed. I guess I just had to get dirty to properly figure out my issues.

I only got a quarter of the way through the fluid flush before I noticed a tear in the boot for my left rear caliper piston. Stupidly, I pushed the piston out all the way so I could put some RTV on the tear for a temp fix. Then I found out the piston was seized. I fought for two hours to get it back in and bent my caliper tool.

So I definitely need to replace that caliper.

As for the other calipers - after a drive, should the rotors be hot at all? And regarding brake drag, should there be none whatsoever? Or is minimal drag that just makes the rotors warm after a drive pretty normal?

A couple things here if you haven't gotten this sorted yet. I just did pads and rotors all around, and RE-BUILT all 4 calipers (one seal blew, decided to do everything for peace of mind). It's in your best interest to re-build rather than to buy an aftermarket re-man caliper. I've not had good luck with them, car or truck. As long as the caliper isn't damaged (the bore) you will have very good luck with a re-build kit and your OEM calipers. I bought my re-build kits with new seals, boots and they came with new pistons as well. If you go new pistons in the rear, you need to swap all of the e-brake internal goodies (the screw) over to the new piston. You can opt not too if those are in good shape.

First thing is don't try to use RTV for a boot tear of any kind. It won't work. I've tried it on various boots (not brake but that would be the worst to try it on IMO). That one for sure will need new seals and a new boot.

Second, if you're working on the rears, to get the piston back in, you're going to need that "re-wind" tool since it's been mentioned that the rears screw in because of the e-brake. I bought my tool (it's a kit) for $16 off Amazon and it worked like a charm. It also works great on the other types of calipers as well just to push the piston back in. It's an all in 1 brake tool.

If you don't have access to compressed air, it's a bit more tricky to get the pistons out, which is why it's good to have new ones on hand. In the rears it's easy...just ratchet the parking brake mechanism and the ball screw will push the piston out.

After I was done the entire process, I had a scary moment where the front brakes were dragging BAD and causing smoke. I didn't know what was up as I had just rebuilt everything, new pads, rotors, seals, boots, and pistons (front), as well as a fluid flush.

If you notice on the front knuckle where the pads ride, there is no metal shim like in the rear for the pads to ride on. The pad ears ride right on the caliper bracket. In my case, I took a file to that surface to knock the scale rust off, as well I took a file to the pad "ears" that were painted until both were down to shiny metal. Added a bit of caliper grease to those areas and all has been fine since.

It should be noted that I added caliper grease from the beginning of the re-build in those areas, but the built up scale on the bracket in conjunction with the painted pad backings was causing the pads to hang up against the rotor and not retract with the piston. They were wedging themselves in there.

Let us know how it goes once you get it all sorted

 

[BeetleDragon737]

Thanks for all the input!

You do realize that you have to twist them while pushing the piston back in on the rears right?

I understand why it came across that way, but yes, I got the wind-back tool from Autozone, compressed the piston + turned at the same time, and it required so much force to turn it that I had to use a wrench on that sliding bar handle to add leverage, and it bent the handle (a lot).

Rotors normally build up heat, when driving, even on a brand new car....
However, it should be minimal

Hmm, maybe my brakes aren't the main cause of my worsened fuel economy then, cause it's minimal heat from most the rotors.

Having old fluid in the system could be the only problem, brake fluid attracts water...water expands MUCH easier that synthetic brake fluid...at a much lower temperature..., thus will make brake pads drag as they heat up....dragging makes them heat more, it's a compounding effect..
Don't evaluate brake performance until AFTER there is a complete and total brake fluid change, getting the old contaminated with moisture stuff out

Helpful to know, thanks. I'll definitely finish that flush ASAP. I still plan on replacing that one caliper at least though.

It's in your best interest to re-build rather than to buy an aftermarket re-man caliper. I've not had good luck with them, car or truck.
...
First thing is don't try to use RTV for a boot tear of any kind. It won't work. I've tried it on various boots (not brake but that would be the worst to try it on IMO).

What about this brand new caliper from idparts? https://www.idparts.com/rear-right-brake-caliper-1j0615424d-bhn276-p-774.html
Swapping all the innards sounds like a real headache, especially cause the outside of mine are so rusted, they're practically disintegrating + not worth saving(especially the carriers).

And I expected the RTV wasn't going to help much, but I figured it was better than nothing. I didn't want to just leave the hole there. Any suggestions for a temporary patch until I get the new one?

 

[csstevej]

Yeah if it’s that hard to twist back it’s time for a new / rebuilt one.......IDPARTS is a great place for parts....you won’t go wrong there.

 

[BobnOH]

......................... Any suggestions for a temporary patch until I get the new one?

Get it real clean, depending on the size hole you could use a bicycle type patch with glue, or RTV or even tape. If it's the one you're replacing, I wouldn't bother.

 

[BeetleDragon737]

Update. I finished bleeding the brakes and found some stuff.

First, both my front brake knuckles look like this:

That's the spot where the pad backing plates slide on the knuckle. I'm concerned this pitting is preventing my brakes from sliding properly. Also, in the 6 years (50k miles) I've had my car, I have not done anything with the front brakes. However, the pads look as thick as they were brand new. Are my front brakes even doing anything?

Second, are brakes supposed to gravity bleed by themselves? As soon as I cracked my bleeder (for my front brakes especially), fluid came down from the reservoir without me pressing on the brakes at all. Does that mean my master cylinder is trash? It was making a loud suctiony clunky sound as I lifted my brake pedal after depressing it more than halfway during the bleed.

Also, the one-man bleeding process - when the brake pedal comes back up, it pulled fluid through the lines the opposite direction, back from the bottle. It didn't feel very effective at all. Is that normal?

 

[KrashDH]

Update. I finished bleeding the brakes and found some stuff.
First, both my front brake knuckles look like this:

That's the spot where the pad backing plates slide on the knuckle. I'm concerned this pitting is preventing my brakes from sliding properly. Also, in the 6 years (50k miles) I've had my car, I have not done anything with the front brakes. However, the pads look as thick as they were brand new. Are my front brakes even doing anything?
Second, are brakes supposed to gravity bleed by themselves? As soon as I cracked my bleeder (for my front brakes especially), fluid came down from the reservoir without me pressing on the brakes at all. Does that mean my master cylinder is trash? It was making a loud suctiony clunky sound as I lifted my brake pedal after depressing it more than halfway during the bleed.
Also, the one-man bleeding process - when the brake pedal comes back up, it pulled fluid through the lines the opposite direction, back from the bottle. It didn't feel very effective at all. Is that normal?

Those front brake pad mounting points most certainly could be the culprit not allowing your pads to slide properly. Mine weren't nearly as bad and they were my problem for sticking.

Front brakes should do about 75% of the work, so something is wrong there with the amount of pad left.

When you crack a bleed screw, even with no pedal force fluid should come out. That's normal.

The noises you're hearing are not normal, but I think it's due to your faulty bleed procedure. You can't traditionally bleed brakes with 1 person. You need 1 person pumping the pedal till firm. Once firm, the person at the bleed screw cracks it open. When the pedal is almost to the floor, the person at the screw closes it. This closes the system while the person behind the wheel pumps again. Repeat until new fluid rugs through the lines at all 4 corners, while keeping the reservoir topped up.

At no point should the system be open on the "up" stroke of the pedal. Only when pushing fluid from cylinder to caliper.

The 1 person bleed needs to to create pressure at the master cylinder reservoir, pull vacuum at the bleed screw, or requires a combo of the traditional pedal pump with special bleed screws that have a one way check valve.

 

[BeetleDragon737]

Those front brake pad mounting points most certainly could be the culprit not allowing your pads to slide properly. Mine weren't nearly as bad and they were my problem for sticking.

My knuckle needs to be replaced then, right? I would be taking off serious thickness there to file out the pits.

When you crack a bleed screw, even with no pedal force fluid should come out.

I guess the people using a 2x4 to keep their pedal depressed are wrong then? The system on our cars is different from others?

At no point should the system be open on the "up" stroke of the pedal. Only when pushing fluid from cylinder to caliper.
The 1 person bleed needs to to create pressure at the master cylinder reservoir, pull vacuum at the bleed screw, or requires a combo of the traditional pedal pump with special bleed screws that have a one way check valve.

Well, oops. I guess our cars are different than others here too. Any way to know if my master cylinder is damaged? Do you have suggestions for a good pressure bleeder I can use if I'm by myself?

 

[BobnOH]

Motive makes a nice pressure bleeder and the proper fit cap. Also, suggest you bone up on the brake hydraulic system and the procedures for servicing.

 

[csstevej]

Personally I use a bicycle pump for my break pedal.....
I pump up the brake pedal , then wedge it into drivers seat lower cushion , go crack the bleeder wait for it to stop and repeat till clear fluid comes out.....never had an issue.

Second you don’t need a whole spindle..... you just need to get the carrier.
It’s held on with 2 bolts.....

 

[KrashDH]

My knuckle needs to be replaced then, right? I would be taking off serious thickness there to file out the pits.

I guess the people using a 2x4 to keep their pedal depressed are wrong then?

The system on our cars is different from others?
Well, oops. I guess our cars are different than others here too. Any way to know if my master cylinder is damaged? Do you have suggestions for a good pressure bleeder I can use if I'm by myself?

I wouldn't replace the carrier yet. I'd file it flat so the surface they ride on is good. Then apply a light coat of caliper grease to it and the pad ears.
Edit; after taking a closer look at your carriers on my phone, I would probably go ahead and replace those. They look like they've been on the receiving end of a hand sledge one too many times

Use whatever you want if you can get it to wedge in there, but you better have good timing and ensure that your reservoir doesn't run the risk of getting too low. Also, these cars pedals are not supposed to be depressed all the way to the floor. Some people will use a small 2x4 behind the pedal from keeping it from bottoming, I've just used my foot also. You can damage master cylinder seals.

I don't know what cars you're working on, but on every bleed on every car and truck I've done in my life, it's been done the same way. There's no event where you want to let the pedal up with the bleed port open or you'll create a vacuum and draw in air and dirty fluid.

 

[BeetleDragon737]

Motive makes a nice pressure bleeder and the proper fit cap. Also, suggest you bone up on the brake hydraulic system and the procedures for servicing.

I've been trying, and somehow regardless of the simplicity of the system, things people are saying for other systems don't seem to apply here. Is there a complete rundown located on tdiclub?

Second you don’t need a whole spindle..... you just need to get the carrier.
It’s held on with 2 bolts.....

This doesn't look like it's held on with two bolts: https://www.idparts.com/steering-knuckle-right-tdi20-1j0407256ag-1j0407256af-p-965.html

And I thought people were saying bearing removal, etc is required to replace.

I don't know what cars you're working on, but on every bleed on every car and truck I've done in my life, it's been done the same way. There's no event where you want to let the pedal up with the bleed port open or you'll create a vacuum and draw in air and dirty fluid.

ChrisFix seems to act as if this is a pretty standard procedure.
https://www.youtube.com/watch?v=n1NvtUwfRJc

 

[KrashDH]

ChrisFix seems to act as if this is a pretty standard procedure.
https://www.youtube.com/watch?v=n1NvtUwfRJc

Take a look at the video again around 5:15...with the person in the truck with their foot on pedal (creating pressure) he cracks the bleed screw. At the end of the pedal depression or slightly before, he closes the bleed screw, then the person at the pedal lets the pedal come up. You have to synchronize so that the closure of the bleed screw happens right before the pedal bottoms out.

Screenshot...notice the writing at the bottom (he has already closed the bleed screw at this point)...noticed pedal is still depressed:

This process is repeated. At no time should you let the pedal come up with the bleed screw open, for the reasons I mentioned before.

In their case, they are putting the pedal to the floor. That's fine for some applications of vehicles, but in ours, you want something behind the pedal so it doesn't touch the firewall...it's not good for the seals.

 

[pj_diesel]

This doesn't look like it's held on with two bolts: https://www.idparts.com/steering-knu...6af-p-965.html

And I thought people were saying bearing removal, etc is required to replace.

That's the steering knuckle, also known as the spindle. The caliper carrier is a separate bracket that bolts to the spindle with two large bolts(I think hex head, and the rear carrier is hex socket-head. Newer models have triple square head for the rear carriers). If you look behind the rotor, you should see them(you might have to scrape away road gunk). They're on really tight, so you'll need a breaker bar to get them off.

Unfortunately, I don't know if they sell the brackets separately from the calipers. At least, I didn't find them with a quick search, but here's a rear one for an example of what they look like: https://www.europaparts.com/caliper-carrier-6q0615425d.html

Also, you might want to check the thickness of your rotors. It's possible they're too thin.

 

[BobnOH]

This explains the brake system hydraulic components pretty well but doesn't go into bleeding-
DIY Auto Service: How Hydraulic Brake Systems Work ..

There are many correct ways to bleed the things. Lots from interweb search. There is nothing special about VW brakes.

 

[BeetleDragon737]

Take a look at the video again around 5:15...with the person in the truck with their foot on pedal (creating pressure) he cracks the bleed screw. At the end of the pedal depression or slightly before, he closes the bleed screw, then the person at the pedal lets the pedal come up. You have to synchronize so that the closure of the bleed screw happens right before the pedal bottoms out.

Immediately after that in the video he does the one man procedure and just repeatedly depresses the pedal with the bleeder open. 6:40 to be exact. I'm not making stuff up out of thin air here.

That's the steering knuckle, also known as the spindle. The caliper carrier is a separate bracket that bolts to the spindle with two large bolts(I think hex head, and the rear carrier is hex socket-head. Newer models have triple square head for the rear carriers). If you look behind the rotor, you should see them(you might have to scrape away road gunk). They're on really tight, so you'll need a breaker bar to get them off.

Unfortunately, I don't know if they sell the brackets separately from the calipers. At least, I didn't find them with a quick search, but here's a rear one for an example of what they look like: https://www.europaparts.com/caliper-carrier-6q0615425d.html

The steering knuckle I posted earlier is one solid block of metal. There are two fingery bits sticking out that the pads ride on. Those are what's badly corroded on my brakes. Only the rear brakes have that extra carrier that you posted. For the fronts, two bolts slide through rubber grommets in the caliper and screw into the knuckle. There is no way to easily remove the corroded item I posted a picture of earlier because it's one piece with the knuckle.

 

[KrashDH]

Immediately after that in the video he does the one man procedure and just repeatedly depresses the pedal with the bleeder open. 6:40 to be exact. I'm not making stuff up out of thin air here.

Neither am I. Having bled brakes MANY times successfully over multiple vehicles, I have never let the fluid flow in the opposite direction that it should when bleeding...which is from MC out the bleed port. You're just gonna suck air and dirty fluid in. Good luck.

 

[pj_diesel]

I guess you're right, I suppose I've done too much work on MKV's and just assumed they were all the same(since the rears basically are). I wouldn't replace that unless I was doing a lot more suspension work. Clean it up and lube it good and see how it goes. If the pads don't sit right you could shim it if it's that uneven.

 

[BeetleDragon737]

Neither am I. Having bled brakes MANY times successfully over multiple vehicles, I have never let the fluid flow in the opposite direction that it should when bleeding...which is from MC out the bleed port. You're just gonna suck air and dirty fluid in. Good luck.

Please, I'm not trying to say this is a good idea! I'm just trying to explain my confusion and find the best solution. Thank you for your previous suggestions. I'll make sure to use a better bleeding method next time, and I won't press the pedal all the way to the floor.

 

[csstevej]

Yes I too stand corrected.....
I just finished replacing all the brake lines and the Rh front wheel bearing on my Silverado....lol that had the carrier as a separate item.....I just assumed.......
My apologies for incorrect info.....