Board logo

Braking problem
Benzine - 18/2/06 at 08:37 PM

This is not my day. I just typed out this thread but then then pc decided to die and lose it all. Secondly this is THE worst internet connection in the entire world, it took ten minutes to load this page.

Anyway about my car...I took it for a 5 mile spin today and there's a problem with the braking. It was fine for the first 4 miles, then it started to feel like the car was braking between gear changes and it pulled slightly to the right. We stopped at tesco (needed to fill up anyway) and then we set off home. Between gear changes at this point was chronic, it was like heavy heavy braking, we couldn't go on so pulled over. The brakes were very hot. Fortunately we had a trailer still hitched up to the land rover a few miles away so got the MK home in no time.

What could the problem be? Siezed pistons in M/C or the brakes themselves? The brake pedal itself needs to fully return each time? The pads? I'm confused and have a headache. Is is something I can fix/any special tools needs?

(Sorry, I would have searched the forum but I can't stress how bad this connection is, I tried many times but the pages wouldn't load) Thanks for any help


David Jenkins - 18/2/06 at 08:42 PM

Make sure that the master cylinder is coming back fully to the rest position - absolutely as far back as the piston can go. If it isn't coming back fully then it can't release excess fluid into the reserve and you'll be running with partial brakes all the time.

David


INDY BIRD - 18/2/06 at 08:43 PM

Just to check are you running a servo or not ???

i had this on a kit b4 and the servo was the problem.

If not could be a piston stuck.

Try re bleeding the brakes only a idea someone else may have a better idea?


britishtrident - 18/2/06 at 09:10 PM

quote:
Originally posted by David Jenkins
Make sure that the master cylinder is coming back fully to the rest position - absolutely as far back as the piston can go. If it isn't coming back fully then it can't release excess fluid into the reserve and you'll be running with partial brakes all the time.

David



Yep --- Sounds very much like a the master cylinder piston is not fully returning --- fluid can't return freely to the resevoir and the fluid expansion as the brakes warm up makes the brakes bind more and more as the fluid temperature increases.

Just a case of some careful checking and setting up of the pedal box


[Edited on 18/2/06 by britishtrident]


britishtrident - 18/2/06 at 09:16 PM

quote:
Originally posted by INDY BIRD
Just to check are you running a servo or not ???

i had this on a kit b4 and the servo was the problem.

If not could be a piston stuck.

Try re bleeding the brakes only a idea someone else may have a better idea?


Usually when this type of problem occurs with a direct acting servo it is because the stub push rod on cylinder side of the servo as had the hex adjusting screw disturbed ---- a couple of mm lost motion is required between the servo and the cylinder or the master cylinder piston won't return fully.


Benzine - 18/2/06 at 10:14 PM

Thanks for the replies. I'm not using a servo. So if it was a stuck piston in the M/C is this something I can fix myself easily enough? I'll get the Haynes manual out now, see if it's in there


JoelP - 18/2/06 at 10:52 PM

i had this last week. If it pulls to one side, its possible just one stuck piston. Next time it doesn it, jack the front wheels up individually and try turning them by hand. Then open the bleed nipples and try again. Then post the results, or have a long ponder!


David Jenkins - 19/2/06 at 08:23 AM

My ex-Escort brake pedal has a strong spring to return it to the 'off' position - when your foot is off the pedal you should have a hint of free play in the M/C operating rod, so you can be sure that it's fully back.

One thing you can try - when this starts happening, stop the car and hook your toe under the pedal and pull. If the pedal moves back and the brakes free off, then a pedal return spring may be a good idea!

David


Marcus - 19/2/06 at 10:50 AM

I suspect it is not the master cylinder, but a siezed caliper piston. After a run, feel the temperature of both front wheels, if one is hot and the other cool, suspect the piston in the hot one.
We've had this twice now on the first car, caliper seal kit cured problem.

Marcus


Mark Allanson - 19/2/06 at 12:01 PM

Don't forget to check the much overlooked rear adjusters. If they fail, they push fluid back into the system and the only place it can go is into the front calipers, causing similar symptoms.


bob - 19/2/06 at 01:06 PM

I'd check the pedal box set up 1st, make it a process of elimination.


David Jenkins - 19/2/06 at 03:12 PM

I'm with Bob - start with the bleedin' obvious and the 'easy to fix' options, eliminate any problems in those areas, THEN work towards the harder problems.

It's piggin' annoying when you think it's something complicated, spend a load of time on it, then find it's really something trivial!

DJ