TheSamba.com :: View topic

Tue Mar 20, 2012 10:22 am

This one has me stumped, 89 jetta. Brakes were fine until master cylinder went out, and there were no brakes. Replaced the master all is well for a month or so. Then the front brakes start dragging half of the time. The pedal starts braking at the very top instead of 2 inches down like normal. So I replace pads rotors and brake hoses, thinking the hoses were blocking fluid from coming back out of the brake caliper.
That didn't fix it... so warrantied out the master cylinder (A1 from Carquest) drive around the block and its fine. Drive it to work Monday its fine, on the way back from lunch the pedal does the same thing. Starts brakeing at the top and the pads are being held against the rotor enough to feel a loss of power and them stopping you without having to push the brakes. I though maybe the brake rod needs adjusting some, look under there and its not threaded for adjustment. So any clue what is next?

Tue Mar 20, 2012 2:14 pm

The next step may be calipers, you can try and find a rebuild kit or just buy rebuilt ones. Since you replaced the master and rubber hoses

Tue Mar 20, 2012 2:24 pm

I though that 2 but what are the chances of them both going out at the same time... Both sides are getting hot and dragging.

Tue Mar 20, 2012 2:49 pm

It is a possible, what about maybe a hard line has a kink.

Tue Mar 20, 2012 3:17 pm

po7g wrote: It is a possible, what about maybe a hard line has a kink.

Cant be they are all straight.

Wed Mar 21, 2012 5:13 am

Sounds more to me that you have no "freeplay" at the MC when you installed the new one.

Fred

Wed Mar 21, 2012 5:42 am

Thats why I was looking for an adjustment, but still doesn't make sense that it doesn't build the extra pressure until 15 minutes of driving.

Mon Apr 02, 2012 10:14 am

Ok Calipers were original so went ahead and replaced them. Worked great for a short trip. Then on the way back from work same old thing. I've got the rod off the brake padel right now to see if there is any adjustment there. Might have to take the master cylinder off and see if there is any adjustment on that side..

Tue Apr 03, 2012 3:17 am

What about Brake Booster, make sure it is working properly and the vacuum is working for it

Tue Apr 03, 2012 5:47 am

po7g wrote: What about Brake Booster, make sure it is working properly and the vacuum is working for it

Took some time to do some diagnostic on the junker. Drove it until the brakes were sticking agian. Jacked up one side of car, sure enough still locked up. I went to the master cylinder and loosened up the 2 nuts holding it in. When the master moved forward the brakes unlocked instantly. So removed the master to see if there were any adjustments that could be done to the rod.
Looked inside of booster and noticed it was full of brake fluid from one of the first 2 bad master cylinders..... Drained the fluid and cleaned out booster. Went under the dash no adjustment on the rod there either. So took it for a test drive, started stopping closer to the top after a short ride. So pretty sure the problem is still there, drove it to work this morning there is no play at all in the pedal before you start to stop after stopping about 4 times.
So is there a way to adjust the brake rod? Or is it getting to much vacuum. I'm a aircooled guy so this Jetta has been a 80's vw learner for me.

Tue Apr 03, 2012 5:48 am

Besides if the booster was not working wouldn't it be harder to stop, it stops fine with not alot of pressure. Just gets to where it wants to stop all the time..

Tue Apr 03, 2012 9:53 am

maybe you can try stacking some washers between the master and booster to see what that does. if that works, then maybe leave it? or get a brake rod from a junkyard and shorten it yourself.

Tue Apr 03, 2012 10:39 am

tripicana wrote: maybe you can try stacking some washers between the master and booster to see what that does. if that works, then maybe leave it? or get a brake rod from a junkyard and shorten it yourself.

I could use the washers for a temp test, but it would cause a major vacuum leak to the booster. It was better today, didn't drag near as much as before. I'm still leaning towards grinding down the pushrod. Just want to make sure Im not putting a band aid on a much larger problem.

Tue Apr 03, 2012 11:48 am

Are you positive that you are getting the correct master cylinder? I believe they are different depending on where it was made (German, U.S., and Mexico) Off the top of my head I want to say that German cars got the Ate master, the U.S. cars got the Bendix and I am unsure about the Mexican cars. Then there is a difference between abs and non abs cars ect...

Like I said this is all from memory but if you call any parts store that specializes in Euro parts they will probably know all of the VIN's and whatnot.

Tue Apr 03, 2012 11:53 am

I made sure to let them know German no abs. I even went to A1 cardones site to check the numbers again shows the same.... So now just scratching my head. I don't have the cash to just order another one right now hoping it will be right..

Tue Apr 03, 2012 8:35 pm

can you take a picture of your brake booster line, does it have a valve on it that keeps the vacuum from leaving the booster?

Wed Apr 04, 2012 5:52 am

po7g wrote: can you take a picture of your brake booster line, does it have a valve on it that keeps the vacuum from leaving the booster?

Yes all of that is there and the booster is acting the way it should I tested it first thing in the morning put my foot on the pedal pumped it up. Then cranked the car and the pedal goes down. On a good note I have a good idea what it is. I was able to get ahold of one of my buddies that does alot of the diesel vw's.
In the past he has gotten master cylinders that the internal plunger was tapered and the push rod did not seat into the bottom. Causing the same problem I am having. So when I get a chance I'm pulling it again to see if it is seating correctly. Might just have to get a drill and open up the taper.

Sun May 06, 2012 5:19 pm

You might check /replace the soft lines to the brakes. I know it happens frequently on air-cooleds that the soft lines get to where they will swell on the insides causing the brake fluid pressure to not relieve after you step on them a few times. Had a Ghia I was flat towing once that this happened to. Once I realized there was something wrong I discovered the rotor glowing red hot & the wheel on fire. I dunno, but the way it comes & goes I think this could be the problem.
-Laurence

Sun May 06, 2012 6:50 pm

It was the master cy causing all the problems the reman was not correct. It was the only one that was offered except it was not right the 3rd one I got was a oe one that was remained worked perfect.