gettting hot - replaced rear brakes with ceramic

Hi folks,


So I had a rear brake pad stick and ware down really quickly, so I went ahead and replaced the rear pads and rotors (I had done front and back pads & rotors about 2 years ago, the front were ceramic, rear TWR and rotors all around Fremax high carbon).



I went with Akebono rear pads with Fermax High carbon rotors.I didn't mess with the fronts, they look good with lots of pad left.


I just got back from work, which requires a fairly long curvy downhill drive. The rear wheels were very hot, on both sides, while the fronts were only warm.



I'm concerned about why the rear brakes were so hot, any ideas why this might be and what I should do to fix it.


A4 wagen 2003.

Thanks!

Did you bleed the brakes, or flush them?


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I did not bleed the brakes or flush them. I just pushed the caliper piston in (using the appropriate tool to twist it in) with the brake fluid reservoir open.

take the wheels off. spin by hand, if the rears dont spin nicely then something is wrong

Did you clean the caliper pins and everything else? You have to have dragging pads or emergency brakes. Jack it up and spin them and see if they spin free. If not find the dragging parts.

to note, some pads have a coating on them (usually blue or red) this is designed to create heat for bedding in the pads with out having to do a bedding in procedure on the road. also new pads usually make more heat when they first bed in anyways, not a crazy amount but surely get warmer. food for thought! my bet is on stuck and old grease in the slide pins.

I greased the slider pins when I installed the brakes. I'll spin the wheels a tomorrow and see what's happens.



I'm wondering if the it's heat from bedding in, I've only driven about 20 miles since installing the brakes, and the drive home is about 10.

Cheers

This happend to me once. Bit I did install a reman caliper. There was a few bits of sandblasting media that was binding the piston.
This was on the G30HD van.

I just put the same set up on the rear of my daughters Jetta.

I had this happen on my golf once. Up north here in the salt belt the lower slide pins are prone to seizing in the caliper bore. One of the methods of freeing them up is to use a hammer and screwdriver/chisel behind the head of the pin to remove them.

I had a pin with a head that was slightly bent, I didn’t see it at first and could not figure out why the brakes on my driver side rear wouldn’t work correctly and release. E-brake was fine but every time I tightened the caliper nut on those brakes I couldn’t turn the rear wheel.

Finally I noticed the pin head was slightly out of line with the shaft, I fished in my parts bin and found a straight one, replaced it and it’s been working fine since.

How are the parking brake cables? These are a pretty much normal failure item on these cars. Look for rusted bubbled sections down low where it hangs down under the beam.

You may also have an issue where the FRONTS are not working as well as they should, take them apart and clean/lube the slide bolts and pad perches.

And flush the fluid!

oilhammer said:

How are the parking brake cables? These are a pretty much normal failure item on these cars. Look for rusted bubbled sections down low where it hangs down under the beam.



You may also have an issue where the FRONTS are not working as well as they should, take them apart and clean/lube the slide bolts and pad perches.



And flush the fluid!

Click to expand...

^^^that^^^
And, the reason I asked if you bled, or flushed is air expands. So if you somehow got air in the lines then they will get hot like that.
I would bleed them and work on the ebrake release. They sell springs to help the ebrake release just because of what OH mentioned above.
Chances are you're having an issue with them if you didn't need to replace the fronts and they were meaty.
Generally every other front brake change you need to replace the rear. If you're changing the rear alone then usually the ebrake is dragging.

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As long as you've done regular brake fluid flushes there is no reason to do it when servicing pads and rotors if you don't open the hydraulic system. You do need to monitor the fluid level when you compress those calipers. From the little experience I've had with those rear brakes, the calipers are not very rugged. But I suspect your parking brake.

When you have old fluid, changing the pads will force most of the fluid back up into the res and basically do a mini bleed for you but if you didnt do the fronts then it could be that the fronts are not working as hard. Its possible with really old fluid. Brake fluid generally is only good for 2 years. Some more, some less. Quality stuff, less. Bleeding the fluid should be done each brake pad change. Pads usually last a year or 2 in the rears so it would not hurt anything to go and flush it just to rule it out

Hi all,


Thank you for the input.



I checked the rears and they spin pretty easily, the rotors are pretty rusty today due the rain the last few days, but I could get the wheeling to spin about two times around, with only slight rubbing of the pad on the rotor (again, I think from the rust), I didn't feel any binding.



I'm thinking maybe my fronts are a not moving as easily as the rear since I really went out of my way to clean everything up well on the rear, but I didn't mess with the front at all and we salt the roads up here. I'll pull the fronts apart and clean and lube so hopefully that works.



I also need to change the brake fluid, its been over two years.



Cheers

How many miles are on the car? I had a problem with my rear brakes where they would not release properly. I did a pad swap and problem went away to return several months later. I was also showing excessive pad wear on 1 pad only. I grease the guide pins at all brake services, long story short, put new rear calipers on from Id Parts, problem went away. Might be time for new calipers, they are fairly inexpensive when you factor in how many miles most of us put on these cars. I would do both sides at the same time.



https://www.idparts.com/rear-left-brake-caliper-a4-p-763.html
https://www.idparts.com/rear-right-brake-caliper-a4-p-774.html

After a short drive the other day, I noticed that the front brakes where pretty cool, while the backs were HOT.



I pulled the front calipers today and greases the slider pins and the contact point between the brake pad and the carrier. I then took the car for a short drive, and while feel is improved, the back were still much hotter than the fronts.


The back wheels feel like they spins freely, I get about one full rotation with a good push, so I'm not sure that they catching, rather it seems like there is just more braking force coming from the back.



Is there any particular way to know if the calipers have gone bad (other than leaking)?



I'm wondering if the issue is with the front rotors not working well.


I'll be doing a fluid flush shortly, hopefully that will help.


Cheers and thank you

Weird things about the rear brakes is they won't necessarily feel like they're dragging as much.

That said, the front could very well be the issue. Not trying to push you into spending more money, however, you should consider replacing all the calipers.
Rear brakes have more issues because of the e-brake and both front and rear have issues due to corrosion.
You should set the e-brake and then try to spin the rear wheels to see if it changes at all.

its REALLY easy to rebuild disk brake calipers and CHEAP too.
a 3rd hand putting the boots back on really helps, or make a sleeve out of cardboard or 3x5 note card stock.
i hate buying reman calipers, i have had some stuck with sand in them from the reman process before and had to be rebuilt anyways so its best to just rebuilt them yourself, unless the piston is pitted so much that its leaking past the seal.

my brother used to date a chick with a Jetta. she had almost 400k on the 03. original brake fluid im sure.


they broke up, her dad eventually got her car, and I still see him driving it around to this day.... still stops with 400k old brake fluid??


my last car; same deal... 350,000km. I towed a bike trailer through colorado and back. twice. 9% grades several times. up and down. car stopped fine? how hard are you guys running these things to make your brakes fail due to old fluid?!?!

fouillard13 said:

my brother used to date a chick with a Jetta. she had almost 400k on the 03. original brake fluid im sure.


they broke up, her dad eventually got her car, and I still see him driving it around to this day.... still stops with 400k old brake fluid??


my last car; same deal... 350,000km. I towed a bike trailer through colorado and back. twice. 9% grades several times. up and down. car stopped fine? how hard are you guys running these things to make your brakes fail due to old fluid?!?!

Click to expand...

When was the last time you did your own brakes?
Usually their flushed by bleeding properly...

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I did my brakes the last several times, it was about 3 years ago.



No I did not chance the brake fluid then, but it was changed ~ 40K ago.


Any suggestions out there about to isolate the issue as coming from the front or the back calipers?

I would flush them and cycle the abs valve with fresh fluid, there's a how to...
If there's air in them they'll add pressure when the air heats up and cause then to get hot like that. I've had it happen on an old Nova. Got bad enough to make the brakes apply when I released on a down hill slope one time. Scarry crap to experience.

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I should I responded to Oil Hammer's e-brake cable question.



The e-brake cable looks fine, the cable slides smoothly.

Any suggestions out there about how to isolate if the issue is coming from the front calipers or the back calipers?

Thanks