Very Long Brake Pedal Travel

[mallone 1]

Afternoon all,

 

Long time lurker here who first of all wants to say thanks for the wealth of information on 205gtidrivers.com. Over the past 10 years or so you've helped me keep a bunch of 205's on the road. Couldn't have done it without the site. Cheers!

 

Unfortunately I've run into an issue I cant solve, and is driving me mad, so time to turn to the forums...

 

Over the past 9 months or so I've been doing a bit of a rolling restoration on a 1.6 GTi that I managed to pick up fairly cheaply. Worth me giving you a bit of background on what's been replaced/repaired so far in case that impacts things...

 

It had been sat for around 3/4 years outside in a yard and was looking particularly sorry for itself. The main issue it had when I picked it up was that at some point in the past (and probably the reason it was laid up) is that it had blown a flexible brake hose and that had drained most of the fluid out of the MC. When I first got it, it had no brakes at all. Pedal straight to the floor. I think that the guys who had it before me had tried to repair the issue but I can't be sure, the car had zero history, so I can't be sure that the car is using it's original braking components. In order to get it through it's first MOT it needed a bunch of stuff sorting, including:

 

O/S Driveshaft

N/S Wheel bearing

N/S Brake caliper

New drum cylinders

New discs/pads & brake pipework

A million other small things!

 

After sorting everything out it got through the MOT without issue BUT with a particularly long brake pedal. Everything bled up ok (using a pressure bleeder if that makes a difference), and the car had perfect balance on the brake test machine, but the pedal was very very long. Felt like a good couple of inches before you get any real stopping power. It will happily lock the fronts if you really go for it on the pedal, and it will pull up quickly without pulling to one side etc but generally it feels pretty horrible, especially at low speed, with such a long pedal.

 

Did a bit of research and it seemed like it might be the servo pushrod that was causing the issue. At the same time it seemed sensible to replace the M/C given that it probably wasn't at its best if it had been sat for years half empty.

 

Whipped the old M/C off and checked the dimension on the servo rod. Was in broadly in spec, being around 22mm from the tip of the domed nut to the face of the servo, and then put the new M/C on. Bled everything up again and it's made absolutely zero difference. If anything it feels slightly longer! Frustrating!

 

When rolling along at slow speed with no pedal application there's no brake drag at all. Feels nice and free. During the 'dead' travel phase of the pedal you can hear slight pad to disc contact (or could be the drums, hard to tell...), enough to be able to do low speed braking in town (<10mph), but you need a good couple of inches of travel before the pedal gets firm at all. With the engine off you can pump the pedal a couple of times and it feels fairly firm. Holding the brake when starting and it sinks an inch or so, suggesting the servo is working correctly.

 

Otherwise I'm stumped. Short of making massive adjustments to the pushrod that would take it WAY out of spec I can't work out what would be causing the issue.

 

Is there any other adjustment I can make to try and get a better pedal? Should I be thinking about another servo?

 

Any help very much appreciated!

[allanallen 528 2 Cars]

I'd personally adjust the push rod up, doesn't need huge adjustments to make a big difference. I also wouldn't worry about taking it out of spec.

 

Are the rear drums adjusted up properly?

Edited November 23, 2015 by allanallen

[Anthony 1,003]

As Allan says, are you sure that the adjusters on the rear drums are working/adjusted properly? They can be a pain and have caused long pedal travel for me before.

 

If they're not adjusted properly, you're using a chunk of the pedal travel just pushing the shoes out to the point where they're touching the drum.

[Tom Fenton 1,542]

Easy way to test, drive along at 30mph or so, pull the handbrake up so the rear drums are just dragging, then try the foot pedal. If the pdeal is now shorter then the drums need adjustment. In my experience the auto adjusters are not auto and do not adjust.

[mallone 1]

Good point about the rear drums. I've not done anything to them as I thought they self adjusted?

 

If it makes a difference, my handbrake is really solid, only a few clicks needed. I assumed that meant things were likely pretty decent on the drums.....

[Tom Fenton 1,542]

The handbrake can be adjusted up on the cable to work OK but its the adjuster inside the drum that dicates the foot pedal.

 

Wind the tension OFF the cables then adjust the shoes up to the drum using the serrated wheel, you can poke it round with a screwdriver through a wheel bolt hole.

 

Keep pressing the foot pedal to centre the shoes up. Adjust up till the shoes are JUST tickling the drum.

 

Then last operation adjust up the handbrake cables.

[mallone 1]

Ok. That all makes sense. Now I feel stupid!

 

Don't suppose there is a good guide/thread that shows the 'poke through the hole' method in detail is there?

 

Thanks for all the help so far.

[Tom Fenton 1,542]

If you pull a drum off one side you can see how the mechanism works, on my own 1.6 GTI I fitted brand new shoes, drums, cylinders, adjusters, springs etc, and even then it doesn't adjust itself very well. If the drums are good with no lip then you can adjust the shoes up by pulling the drum on and off as you are adjusting.

[allanallen 528 2 Cars]

Love a bit of poke through the hole!

 

Just look through a bolt hole and find the adjuster (multi sided star nut) them poke it round to adjust the pads up.

[erbs 42 1 Cars]

i also have this same problem with long pedal travel,unfortunately my car is in the body shop, i adjusted the rear drums before it went in and my mate said that very little braking power when his foot applied to the pedal,so will have to look into it when i get the car back

[mallone 1]

Great stuff. I'll give this a go over the weekend and will let you know how I get on. Appreciate all the help.

[mallone 1]

Quick question: If I'm going for the 'poke through the hole' method is it obvious which way I should be turning the adjuster?

[Tom Fenton 1,542]

Downhill on both sides, that is the way the auto mechanism turns them to adjust up.

[mallone 1]

Ok, so spent this morning giving this a go and have had a pretty frustrating time.

 

Firstly, took all the tension out of the handbrake cables via the adjuster at the back of the handbrake handle. It was done up really tight, with only one or two clicks needed to go really solid. Wound the nut right out and let the cables slacken off. Is there anything else I need to do to reduce that tension or is that adjuster enough and the cables will do the rest themselves?

 

Got the car up on axle stands and got the wheels off.

 

Both drums were spinning pretty freely and after a bit of messing about with a torch and a screwdriver I was able to adjust up the little ratchets inside. Both turned down a few clicks until the drums were starting to tighten up a bit and weren't spinning as freely. Brakes pumped a few times to level everything out.

 

Adjusted handbrake up as per Haynes manual, with the handle on the seventh click etc.

 

Wheels back on, off the stands.

 

Started car, took it for a spin and the brakes feel exactly the same. No difference at all. Still a massively long pedal. So frustrated!

 

Any other suggestions? All comments appreciated!

[Tom Fenton 1,542]

If that hasn't made any difference then you will need to look at lengthening the servo rod.

[mallone 1]

Ok. But it just doesn't seem normal to have to adjust the servo pushrod so far out out of spec. Just makes me think something else isn't quite right...

 

Additionally, as I mentioned in my first post, you can actually feel the brakes working, very slightly, during that 'dead' travel on the pedal. Surely that indicates there's some pressure going through the pedal to the M/C? Would the handbrake cables being so tight have caused any issues with the rear drums?

 

Sorry to keep asking what might be stupid questions. I'm completely stumped!

[Tom Fenton 1,542]

The handbrake being so tight may well have worn the shoes in a funny way. Be worth pulling a drum off one side for a look I suppose!

[mallone 1]

Just wanted to follow up on this in case anyone finds this on Google in future and wants to know what was causing it...

 

I didn't really have the tools or workspace at home to be able to really get the rear drums apart so decided I needed to spend a bit of money and give it to someone who really knew what they were doing.

 

Got the car booked in at a local Peugeot specialist nearby and after he spent some time poking around everything found two things:

 

1. The rear drums had been setup incorrectly and the leading shoe (on both sides) was failing to engage with the drum properly. The bottom of the shoe was hitting the drum face first. Was causing issues with uneven wear, as well as meaning that some of the pedal travel was taken up by having to 'pivot' the shoe into fully engaging with the drum. He spent a bit of time sorting this out, admitted it was likely a small issue in the grand scheme of things as...

 

2. The rear brake compensator mounted to the chassis leg in the engine bay was knackered. Either through being run dry when the car was laid up or just general failure through age, was refusing to bleed up correctly.

 

Decision made to (for now at least) cut the compensator out of the circuit. System bled up again. Perfect pedal. Finally, job done!

 

I'm debating what to do about fitting some sort of compensator or bias valve in there at some point, doing a search seems to through up a lot of opinions...

 

Either way, thanks for all your help and comments!

Edited December 8, 2015 by mallone

[erbs 42 1 Cars]

can you still get the compensator new from peugeot? the one that lives in the engine bay?

[farmer 328 1 Cars]

That compensator isn't available

[erbs 42 1 Cars]

Where you buy these now?

[farmer 328 1 Cars]

Haven't come across them aftermarket, maybe some others have ?

 

I keep them as I came across them at dealers over the last 5 or 6 years.

[mallone 1]

Can you run the inline, 1.9 style, compensators on the 1.6?

[Anthony 1,003]

I've never tried it with drums, but you can certainly run a single inline 1.9 compensator to feed both rear brakes on a 1.6 style pipe layout with disks on the back.

 

Given that there's no issue doing a disk conversion with the 1.6 compensator still fitted, I imagine it should be fine the other way around too, using drums on a 1.9 compensator.

 

Sounds like you've been quite unlucky though as the 1.6 compensator is generally very reliable indeed and failures rare (unlike the 1.9 type)

[smithy72 1]

I know this is an old post, but just wanted to report that I had tried everything to eliminate the long pedal travel. I had bled and rebled the brakes over and over, its all new components, so I tried bedding everything in as much as possible.

I thought, like the OP, that it was due to the pedal rod in the Servo not pushing the Master Cylinder. I assumed a different standoff,  due to production differences, since I had a new master cylinder.

 

I never suspected the compensator (until reading this post) as I could here the ball moving freely inside it. However I have removed it and put a female to female union in its place and instantly the pedal is back to normal height.

I just wanted to post to update this thread and confirm that maybe these components are starting to fail and highlight that its somethign to check if similar symptoms. (My car hasnt been used in 20 years which is likely to have contributed!).