MK4 Golf/Jetta/Bora clutch problem

Hi everyone. Maybe my problem is already solved and explained somewhere in forum, but I was unable to find.

I'm driving 2002. 1.9 TDI 74kW. Last year I replaced clutch completely (DMF, clutch disk, pressure plate, release bearing).
Even before changing, clutch engage point was in lower region but not extreme.
After changing kit, clutch pedal became soft and engage point is just near from floor, and there is almost ne resistance in upper half pedal movement. I changed slave cylinder with new one but there is no change. After that I changed master cylinderwith used one (used about 2 year but sit on shelf about 10) but there is no change again (the new one at the moment was unable to find).

I changed oil fluid and drained it several times and situation remained same.

What can be the problem? Is the master cylinder or something else?
What can it be.

The arm/lever that moves the throwout bearing can crack and bend over time causing similar symptoms (engaging right at the floor). I have some measurements here to check:http://forums.tdiclub.com/showthread.php?t=333365

The pivot bal that the arm pivots on can cause problems too. I've also had a bad flywheel do that but you had the same symptoms before/after.

Thank's! I will soon go to service to see what to do

Hold on a minute. I'm trying to understand, when you push the clutch in, it's soft? When you let it out it releases near the floor? Define what you mean by soft. A new clutch will release next to the floor, as they get older the release point gets higher. Thats one of the ways you can tell you need a replacement. Does it grind going into gear? Any gear? Other than once in awhile when you let your foot off the clutch to soon. I guess what I'm trying to say is, other than the "soft" issue it all sounds more or less normal to me.

Did you bleed the clutch? Here is a write on that procedure.

http://www.myturbodiesel.com/wiki/brake-fluid-and-clutch-bleeding-and-flush-mk3-and-mk4-vw-and-audi/

Tdijarhead said:

Hold on a minute. I'm trying to understand, when you push the clutch in, it's soft? When you let it out it releases near the floor? Define what you mean by soft. A new clutch will release next to the floor, as they get older the release point gets higher. Thats one of the ways you can tell you need a replacement. Does it grind going into gear? Any gear? Other than once in awhile when you let your foot off the clutch to soon. I guess what I'm trying to say is, other than the "soft" issue it all sounds more or less normal to me.

Click to expand...

Agree on what above said. Please tell us what are problems you are experiencing that you don't like current operations of clutch pedal? If vehicle operates fine and you are just not liking how clutch pedal feels then its ok. What kind cluth kit did you installed, if I understood you replaced DMF with single mass flywheel or with new OEM DMF and clutch disk, pressure plate? if so then its normal to have your clutch start engaging right at floor (thats a very good thing as means disk isn't worn out) and soft clutch pedal is normal lot of times with factory new clutch setup. What happens as vehicle ages and your old clutch wears out it gets bit stiffer to press/release clutch pedal then when its new. So after years of driving you get used to it and start thinking that its supposed to be that way and not realizing how it was once new. This is very common complain I get from customers whenever we replace clutch or new brakes with brake fluid flush, person gets used to the way their car behaved for long time that they forget how it supposed to be when everything operates flawlessly smooth.

When I mean soft I mean it's softer than a accelerator pedal The clutch hydraulic system is filled with new oil and bleeded with vacuum.

When I press pedal, first half there is no resistance at all, and after that (second half pedal travel) I feel a tiny resistance.

When shifting there is small grind when shifting faster than normal, but there is no grind when shift slowly and wait the shifter goes by itself.

I know that with new pressure plate clutch must be lower, but my engages right about 1/4 inch from floor. I don't know is that normal? I tried in other cars (all golf mk4 tdi) and their clutch engages in upper section (but they didn't changed clutch yet).

plavis,

If on the workbench we setup a flywheel, diaphragm pressure plate and disc all matching parts bolted together and measured the release load required to release the clutch, and then recreated the same test with a thinner wornout disc the release load of the worn disc setup would be noticeably higher. This is a characteristic of a diaphragm pressure plate.

This above statement does not apply to Self Adjusting Clutches.

In addition a general cleanup of the fork pivot, bearing quill etc reduces friction reducing the release load too.

It is a common observation and the follow up question is, Does the clutch slip under power? No, enjoy the lighter pedal your car used to have.

A hydraulic release system starts to create pressure almost immediately. It only has a slight master cylinder pushrod travel then ramps up the pressure according to the load it has to overcome from the diaphragm spring.

I assure you that the amount of fluid used, wasted etc is not a guarantee of a fully bled system.

Many different techniques to bleed the hydraulic system, one or two that might help.

Remove the slave cylinder is as low as possible and holding it so that the line connection is the high point, pushrod slightly down. Smoothly compress the slave cylinder several times flushing fluid and bubbles back out thru the reservoir. The bubbles break in the reservoir, replaced by fluid. The pedal must be fully up for this technique.

A variation on brake bleeding, 2 people required:
Tubing on slave cylinder bleed screw to waste container.
Open bleed screw, 3/4-1 turn.
Slowly push clutch pedal down.
Close bleed screw.
Lift pedal up.
Repeat.
Focus is on flushing from master cylinder down. Getting a flushing action from the MC rather than a marginal response from the slave cylinder as the bleed screw is opened.

I used the second technique on a Hyundai Genisis 2.0L Track Turbo with an internal slave cylinder and we got the system bled in a few minutes.

Gary

Thank's Gary!

I'll try to bleed again using your advice.

I forgot to mention that when outside is warm, things are better. The part with no resistance is shorter, and engaging is about inch from floor. This morning when I'm droving car out of garage (where is cold) engaging is right to the floor. I drove about mile, and left car outside (today was warm outside and sunny) for about half a day, and when I go for a ride, the pedal was much better and engaging aboit inch froom floor. Is this connected with air bubbles (on heat expanding)?

plavis said:

Thank's Gary!

I'll try to bleed again using your advice.

I forgot to mention that when outside is warm, things are better. The part with no resistance is shorter, and engaging is about inch from floor. This morning when I'm droving car out of garage (where is cold) engaging is right to the floor. I drove about mile, and left car outside (today was warm outside and sunny) for about half a day, and when I go for a ride, the pedal was much better and engaging aboit inch froom floor. Is this connected with air bubbles (on heat expanding)?

Click to expand...

The best way to bleed any air out of brake/clutch system is using pressure bleeder as sometimes vacuum or old school way isn't efficient enough to get all trapped air out. Get a motive power bleeder or equivalent tool, then attach to master cylinder reservoir and apply about 15psi of pressure then open bleeder at slave cylinder and let air/fluid escape for 15-20secs, re-tighten bleeder and release pressure and check your clutch pedal if it feels good, repeat steps till normal pedal feel reached. If you don't have access to motive power bleeder, then you can get something like this
MV8500 Silverline Elite Automotive Kit

I tried to bleed clutch i saturday in old fashion way and it came worst.

In conversation with local servicers they all told me that no other brand is making them problem with clutch bleeding, only VW. They told me just to open bleeding nipple and let the oil leeks slowly by itself.

I tried some combination of all methods you described and became better

Thanks guys

Also make sure that there is no play between push rod and the clutch pedal.
My 2000 golf with 430,000km had a worn push rod retaining clip as well as slightly worn clutch pedal pivot bushings.....this resulted in app 20mm of play at the bottom of the pedal before the push rod was even moved.
see...
http://forums.tdiclub.com/showthread.php?p=4614178

Not good again.

Every time i bleed clutch it's excellent, and during a next few days it's going down again.

I also noticed when I pump it few times it's OK during next hour or two.

@maxmoo No. there is no play between pedal and push rod (if you mean within plastic clip)

Again the same. During last 10 days, I was bleeding 3 or 4 times. And every time after bleed is excellent, but after day or two (without driving) fading again.

It must be some of cylinders minimal leaking and drawing air in. I'l check in next days

I realize that you have been bleeding it a lot , but between the bleeds is your fluid at the proper level? Does it for instance between the times you bleed it go below the little tap for the slave cylinder that is located on the right side of your master cylinder? I'm thinking that somewhere you must have a small leak. Any wet spots on the driveway or parking lot?

I didn't noticed leaking under the car because I have plastic cover. Tomorrow I will thoroughly look for wet spots around slave cylinder.

Question: can this be caused by pipe that conecting master cylinder with fluid reservoir?

That's the tap I was talking about. If its leaking yes it could be the problem. The brake fluid should never go below the tap that that hose hooks to on the side of the master cylinder, if the fluid does go below the hole to that hose it will introduce air into your clutch system. So while you are bleeding the system make sure the fluid does not go below the tap, and after you've bled it and drove it for a couple of days make sure the fluid is still above that tap.

Wet spots could also be down the inside of your tires, if a caliper or hose to the wheel is leaking. Remember the brake system and the clutch share fluid from the same resivoir .

Today I removed slave without disconnecting pipe and bleeded by pressing it. All oil returned to reservoir. After that I returned it back and try. Pedal stayed down because there was no oil in system.
Then tried vacuum bleeding and lot of air pop out.
During that I checked for leeks and there is no.

This time, while bleeding, I always kept reservoir full to the top.

The pedal is now very high, the resistance begin after 1/4 of inch, and engaging is about inch from floor.

In the next few days I will monitor situation.

Sorry for wrong typing, it was my phone doing wrong. Now it's edited correctly

Today, I bought new master cylinder and it's even worse.

When installed, I bleeded it and it was perfect. In the next few miles and minutes it's getting worse and worse. Now is worse than ever. I can't go outside city now.

Bleed again, perfect, and after some time again

I don't know what to do anymore

The only thing I suspect that it's possible is the seal between master cylinder and pipe. 02F141143A

Or can it be bad bleeder perhaps?

SOLVED!


Bad slave cylinder! Even brand new, it was faulty.

Thanks everyone!

Good to hear, so would it leak the fluid out or allow air in? Or both?

I didn't see leek on the cylinder rod, so it must be just allowing air in.

Question
1) What pipe?
2) How is your brakes? Solid, changes after bleeding?

Ok, never mind, glad you solved it.

1) I was suspecious about connection between master cylinder and pipe that goes to slave cylinder
2) brakes are just the same. I didn't touch them. Problem was with clutch. Clutch gets oil from same resorvoir buth at higher point so brake never get out of fluid.

BTW, slave cylinder, even new (3 months old) was fault. My mechanic changed it but with aftermarket one. The manufacturer is Topran, now I put Sachs.

Hi, me again!

Have another problem related.

When I changed slave cylinder and bleeded the clutch was perfect. Without empty pedal travel (maybe around 1/4 inch), and with bitting point around half from floor.

During past few days, bitting point was going down (about inch from floor), but without empty pedal travel and with no air bubbles in system.That lasted 4-5 days.

Today I noticed problem that was occasionally showing before in the past. When depresing clutch, about inch from top, there is a glitch with no sound but I feel it on foot. I feel that on other two pedals too. That last for 10-20 pedal pressing and then dissapear. But this time, when this occur, bitting point returned to normal state (about half pedal) and It's great again.

When changing master cylinder I didn't noticed any anomally on pedal. Could it be pedal or release bearing lever (transferred through oil)?