help! - excessive brake pedal travel

[andycook]

Got round to fitting new brake calipers this evening, to solve sticking pistons problem.

Fitting went ok, and I bled master cylinder, then all brakes starting at rear NS, working to front - replaced about 1 litre of brake fluid.
but now a lot of effort is required in braking and one has to push the pedal a fair way.
I didnt have the engine on when bleeding - would the lack of vacum assistance here be a problem?

I notice that when pushing brake pedal with engine off, it feels firmer and less pedal travel than with engine on?

any ideas on how to make the braking sharper? as it wouldnt be that safe to drive on fast roads then way it is now....

andy

[Tallyman]

Sounds like you've still got air in the system somewhere, as it should be rock hard if it's been bled properly. I'd suggest doing it all again but start at the front and work back this time. Make sure you run plenty of fluid through each line to clear out any air. Could also be a problem with the LSPV on the back axle causing this.

[marky]

Silly question ???? how many people where involved in the Bleeding or have you got a self bleeding kit

[andycook]

2 of us did the job,

during bleeding, The engine of car was off. My wife was in drivers seat, I got her to push brake pedal slowly, whilst it was pushed down, I opened bleed valve (tube connected and other end submerged in fluid in a container), let fluid out of tube, closed valve - the missus lifted brake pedal slowly. Repeated with about 10-15 times on each wheel, topping up brake fluid after every 5 valve open/closed cycles.

was that correct?

[marky]

2 of us did the job,

during bleeding, The engine of car was off. My wife was in drivers seat, I got her to push brake pedal slowly, whilst it was pushed down, I opened bleed valve (tube connected and other end submerged in fluid in a container), let fluid out of tube, closed valve - the missus lifted brake pedal slowly. Repeated with about 10-15 times on each wheel, topping up brake fluid after every 5 valve open/closed cycles.

was that correct?

sounds ok to me. give it another try as previously said by TALLYMAN

[Vagrant No2]

I am not familiar with Surf calipers but it may be an air lock in the calipers as they are new . If you crack open the pipe where it enters the caliper and bleed off the fliud , some trapped air may come out . I have done this on many vehicles where calipers are changed . Also try to clamp off all the other brake flexy hoses LIGHTLY with clamps (mole grips) so that all pressure is consantrated on one brake ie the one you bleed .


Rick

[JimL]

4x4wire recommends:

Bleed the longest hydraulic line first, working up to the shortest.

Then bleed the LSPV which is over the rear axle.

When finished start her up, press and hold the firm pedal, knock the engine off, if the pedal doesnt go soft after 15 to 20 seconds then you've done a good job.

[Vagrant No2]

4x4wire recommends:

Bleed the longest hydraulic line first, working up to the shortest.

Then bleed the LSPV which is over the rear axle.

When finished start her up, press and hold the firm pedal, knock the engine off, if the pedal doesnt go soft after 15 to 20 seconds then you've done a good job.

Checking a soft pedal like Jim says also tells you if the master cylinder seals are passing fliud by which means new seals/master cylinder

Rick

[andy]

A 1996 Surf will not have a LSPV.

[andycook]

I will try bleeding again tonight...

is the LSPV the load sensing valve? - to compensate for drums on back?, as it does have a load sensing valve - with a sprung arm at back.
The previous owner had this picked up at an MOT in March - it had seized and was released.
but the brakes weren't so quite bad before I changed calipers last night

With engine running I was able to push the brake pedal by HAND all they way to the end-stop - coudlnt do this with the engine off - but guess this is the vacuum assistance helping when the engine is running.

andy

[Rob]

A 1996 Surf will not have a LSPV.

It ain't a Surf - it's a UK '96 runner which was a 2nd gen with no ABS

[andy]

It ain't a Surf - it's a UK '96 runner which was a 2nd gen with no ABS

Well spotted Rob I didn't see that, but technically I was right, a 96 surf will not have one.

[Maddog007]

digging up a pretty old thread i know,
but quite simply this is the exact same issue im having now. but there has been no update posted on this thread, im wondering how things worked out,

No amount of bleeding seems to work, ive even checked out the master cylinder, gave it a hone, but couldnt get hold of any seals at the time, & they didnt look bad at all. & apart from the seized caliper, the brakes felt strong beforehand.

any ideas,

Im probably going to get some seals for the m/c tomorow to eliminate that.
Its just weird that the pedal feel great when the engine isnt running ?

[gwh200]

digging up a pretty old thread i know,
but quite simply this is the exact same issue im having now. but there has been no update posted on this thread, im wondering how things worked out,

No amount of bleeding seems to work, ive even checked out the master cylinder, gave it a hone, but couldnt get hold of any seals at the time, & they didnt look bad at all. & apart from the seized caliper, the brakes felt strong beforehand.

any ideas,

Im probably going to get some seals for the m/c tomorow to eliminate that.
Its just weird that the pedal feel great when the engine is running ?

worth checking that the back brakes are not out of adjustment,they are supposed to do so by emselves,but sometimes(quite a lot of times) dont

[stormforce]

worth checking that the back brakes are not out of adjustment,they are supposed to do so by emselves,but sometimes(quite a lot of times) dont

this is what i reacon is wrong with mine,especially after 3 trips to Baldhu and in the deep stuff so next weekend i am hoping to get everything stripped down and checked out