Rorie

Active Member
new servo and master cylinder. Pads and discs haven't been touched, but the pipes were replaced at the front only.

Initially the pedal had way too much travel and bottomed out on the floor, so I adjusted the push rod in the servo as the nut was hard up against the bulb on the end. Once done, all was good.

Drove several miles testing the brakes, no issues.

Straight road, not on the brakes at all, I lost power- brakes were on hard- could hardly move the car once stopped. Adjusted the push rod back a bit towards the bulb on the end, all was good.

About 15 miles of testing the brakes, all was good.

Then again, straight road, brakes came on. Stopped, repeated above process, all good.

50 miles later, straight road, guess what! Same again!

the nut on the push rod is almost back to where it started, probably 2 threads away from being hard up to the end bulb!

So, what is going on? Do these items take time to "bed in"? Could it be pointing to a different issue?
I get a really firm brake pedal and don't feel spongy at all. Once adjusted, the pedal does go in further before the brakes activate (as expected), but a few miles down the road I end up with quite a firm pedal that doesn't need moved much at all!
 
new servo and master cylinder. Pads and discs haven't been touched, but the pipes were replaced at the front only.

Initially the pedal had way too much travel and bottomed out on the floor, so I adjusted the push rod in the servo as the nut was hard up against the bulb on the end. Once done, all was good.

Drove several miles testing the brakes, no issues.

Straight road, not on the brakes at all, I lost power- brakes were on hard- could hardly move the car once stopped. Adjusted the push rod back a bit towards the bulb on the end, all was good.

About 15 miles of testing the brakes, all was good.

Then again, straight road, brakes came on. Stopped, repeated above process, all good.

50 miles later, straight road, guess what! Same again!

the nut on the push rod is almost back to where it started, probably 2 threads away from being hard up to the end bulb!

So, what is going on? Do these items take time to "bed in"? Could it be pointing to a different issue?
I get a really firm brake pedal and don't feel spongy at all. Once adjusted, the pedal does go in further before the brakes activate (as expected), but a few miles down the road I end up with quite a firm pedal that doesn't need moved much at all!
the adjuster needs to be set out as much as possible but there must be some free play at the pedal otherwise as you know brake will apply, is pedal spring fully returning the pedal
 
Yeh new springs too when I rebuilt the pedal box.

I'm worried that if I need to adjust again, I won't have any more thread to play with!

Seems strange that at this position, initially the pedal was hitting the floor (while braking effectively). But now I have a rock hard pedal!

Only 'unknown' to me is the rear flexi. It's covered in oil, but I assumed that was out the diff flange as it tracks down around the diff. But today the underside of the tub floor is also covered in oil! It's quite thick cosistancy, so was sure it was just the diff, but could it be a leak in the flexi? Would that cause any of the issues I'm seeing?
 
Yeh new springs too when I rebuilt the pedal box.

I'm worried that if I need to adjust again, I won't have any more thread to play with!

Seems strange that at this position, initially the pedal was hitting the floor (while braking effectively). But now I have a rock hard pedal!

Only 'unknown' to me is the rear flexi. It's covered in oil, but I assumed that was out the diff flange as it tracks down around the diff. But today the underside of the tub floor is also covered in oil! It's quite thick cosistancy, so was sure it was just the diff, but could it be a leak in the flexi? Would that cause any of the issues I'm seeing?
I would think that much fluid on the tub floor would show a very noticeable drop in the brake fluid reservoir.
 
Yeh, looking again, I'm quite sure it's out the diff. And a leak would make my pedal weaker, not stronger!

Any thoughts on the cause / cure to the brake issue?
 
Any thoughts on the cause / cure to the brake issue?
My only thoughts are if you've only replaced the servo and master cylinder then the problem may lie there. Did you buy parts for your Landy or did you buy 300Tdi ones? I've no idea if there's a difference in the connection from the pedal to master in a G reg Landy to the 300Tdi era?
EDIT
Or, for that matter, if there is a difference in the parts!
 
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Ok, so the short explanation of the issue; the brakes come on randomly while driving even when I’m not using the brakes.

The pedal seems to get harder as the drive goes on too.

Could there be an issue with the servo valves?
 
I had this once on my 2A with no servo, or at least something similar.
I'd done servicing and adjustment but had over adjusted so the master cylinder wasn't returning fully which meant fluid want able to return and the brakes wouldn't release
 
Ok, so the short explanation of the issue; the brakes come on randomly while driving even when I’m not using the brakes.

The pedal seems to get harder as the drive goes on too.

Could there be an issue with the servo valves?
yes if rod isnt too long
 
If the nut on the rod is right back up at the 'dome', then must be the servo? Does this mean another new servo?

Kermit, what did you over adjust? The rod?

Any suggestions on what/how to test or issolat to work out what's going on?

The fact I have pressure building in the pedal as I drive is a bit odd isn't it?
 
Yep the rod.

If you have pressure building in the pedal, do you mean the servo is losing vacuum?
Not sure. I dont think i'm losing a vacuum as even 24 hours after the engine stopped, if i pull the hose out the servo there is clearly still a vacuum.

Any other thoughts folks? Really at a loss here!
 

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