How far does your brake pedal travel??

OK, in my eternal quest to solve the braking problems on my cabriolet. It has been treated to new brake lines, new rear wheel cylinders and shoes, and a new master cylinder. BUT I'm not sure if everything is as it should be. I'be finally managed to get rid of all the air in the system i think, but the brake pedal does seem to travel rather a long way before it stops, when it does it's nice a firm, but there's lots of travel before it actually does.  Goes over alfway

There is definitely NO air in the hyraulics, I could pratically bleed the brakes in my sleep I've done it so many times now.  The one bit I'm not sure about, and havn't replaced is the rear brakes compensating valve (you know that horrible array of pipes attached to the rear axle by a spring!) Could this affect the brakes in this way?? If so, has anyone got a known good one I can substitute, as I don't really want to shell out for a new one if I can help it.

Any other suggestions on adustements etc. that i may be able to make are welcome! I'm tearing my hair out here trying to get these brakes working properly!! I will not be defeated!!

Maniac "snap"

I have replaced ALL except the rear compensating valve and find my pedal travel long , but efficient [ish] when it gets there , the last 4 inches that is . When you think its got to travel from the pedal across the engine bay and then start to push the master cylinder its no wonder they work at all . The wife's "modern" car brake pedal moves an inch then wollop they are on , as does my works van .

My system is 100% standard as original intended , are we asking too much from a 20 year old  system that was supposed to be used on the left hand side of the road and being used on the right meant we just have push harder .

Could any one measure pedal travel in cms to see how much movement you get before it bites .

What is the best most cost effective upgrade off the shelf for the MK1 you can do ?

Are me and Maniac alone on this one ?

Cheers Chudd.

The other thing I've noticed, after fidling around in my garage for the last hour, is when you hit the brake pedal hard with the engine running i.e when the servo is working, you geta loud 'clonk'  On further investigation I've found this noise to be coming from the brake compensating valve.

Anyone know if it's meant to make this noise, or if it's at fault when or if it does.  :dontknow:   Note, you have to 'stab' the pedal quite sharply for it to make this clonking noise.  

I think I've got the system as good as it's going to get, so off for an MOT tomorrow to see if it passes this time.  :?

My brakes start to work after about 1/2 an inch, then there is not too much travel after that! Sounds like you got something wrong there guys, though what is this compensator valve you are talking about? I don't have one of these on my car!

Make sure the rear shoes are bedded in and are adjusted fully.  This has the biggest impact on pedal travel imo.  Is the travel reduced with the handbrake on?  Can you pump up the brakes?

Agree, most of the travel is just taking up the slack in the rear drums.

Use the ?pointy stick? method to manually adjust the rear brakes. Assuming the shoes, cylinders and drums are all in tip top condition;

Slacken handbrake cables in the car. Put car in gear.

Remove one wheel bolt. Jack up car so you can rotate wheel, no need to remove entire wheel.

Use a torch to peer in the wheel bolt hole and find the hole at the bottom of the adjusting wedge. (look in Haynes manual for the triangle shaped wedge thingy)
Use bradawl type tool to pull the wedge down.
Make sure wheel turns freely with just a bit of ?drag?
Drop car down and replace bolt
Do other side
Re-adjust handbrake cable.

If after all this there is still a lot of travel you can extend the rod from brake pedal to take up some of the slack in the right to left mechanism.

All the above assumes that the brakes are in good working order everywhere else, its no good doing the above if the front disks are very rusty the callipers seized and the fluids not been changed for 7 years?

Check a couple of things.  Firstly the pipe that goes from the inlet manifold to the servo booster - mine was split and the brake performance was awful.

Secondly, when you bleed the brakes, do it with the car on its wheels otherwise you trap air in the rear cicuit as the regulator can trap air in there.  I bleed my brakes with a Gunson Visibleed pressure bleading kit as pumping the pedal doesn't seem too effective.

Also, bleed them in the order shown in the manual (staring at the back) and make sure all the sliders are free to move…

Early-1800 said

If after all this there is still a lot of travel you can extend the rod from brake pedal to take up some of the slack in the right to left mechanism.

I tried this on mine when I overhauled the brakes and found that as there was nothing for the pedal to push against i.e. no stop, the adjustment of the rod would just move the pedal up or down. On investigation there looked like there should be a stop mounted on the pedal assembly. After fitting a suitable bolt and lock nut to this bracket I was able to take some of the slack out of the system as you describe.

Simon

thanks for the tips guys, I think I've got them about as good as I'm going to get them, so I'm going to put it in for an MOT again tomorrow, and hope they pass this time. I've taken it out, and they feel much better than they did, but still not as good as I think they should, the pedal still travels further than I would like. Fingers crossed it will be good enough to pass though.  

If not, then I'll have to frustratingly take it to a garage and let them fix it, and admit defeat, which I hate doing!!

Cheers

Mike.

Maniac

      Now mate, as you know i have the same problem as you or should i say did .

     What i found -and thanks to those who posted reply's -is that my pedal moved at least 40mm [1 1/2 inch] before it did any thing , this was due to the rod from the pedal and the rod from the first joint being slack . I have taken up all the slack using the recommended measurements and now find that my pedal is ton's better . There's a couple of pages with dimensions in the Haynes manual .
Probably the reasult of 25 years of wear and tear , the pins and remaining joints are fine . My pedal now sits at the same height in the car as the clutch pedal , before that it was higher .

Good luck with yours , try the above with a helper pushing the brake slowly and see if you have the same slack linkage problem as my car ..

Yes there was some slack in mine, which I adjusted out. I think is was mainly because I've replaced the master cylinder with a non-VW part, so I expect it sits a bit differently. There was only a very small amount of slack in it anyway. It still goes down a long way before there's any real stopping power.  The feeling is that typical of when there's some air in the hydralics, but I'm sure there is none, it's had nearly 2 litres of fluid pushed through it using a gunsons easibleed kit, and it hasn't got any better.

Like I say the only thing I've not replaced is the rear compensating valve which doesn't leak or anything, but I'm suspect about because it makes a 'cloking' noise when you jab the pedal hard.  I'm going to see what the MOT people say first, if it passes an MOT then I'm happy to drive the car the way it is then maybe put it into a garage (when finances allow) for it all to be set up properly sometime in the future. The system is tonnes better than when it went for its previous MOT which the brakes failed on. I'll let you know how it goes.   

Mike.

Maniac
         that compensating valve is supposed to clunk under heavy braking , its job is to stop fluid locking the back wheels under heavy braking so it shuts the supply and transfers the effort to the front . I think they are ?60.00 ?? . so i will leave mine till a last resort . Have you replaced or checked your flexey hoses ? One of them may be balloning ?

Cheers……..

Yes, the car's got new flexi hoses all round, new copper brake lines all round, new rear wheel cylinders and shoes, new front brake pads (discs are ok) and a new master cylinder.  It still feels not right though.  

MOT tomorrow, we'll see what they say.

Mike