Binding brakes. HELP!!!!!

[sambo]

Still having brake isset issues

 

The front calipers seem to bind ever so slightly and get slightly worse when they get warm.

 

I have tried everything now!

4-pot calipers and a bias box.

 

 

I tried adjusting the master cylinder rod but nothing seems to help.

 

I have wound the rod as far into the clevis, then spaced the cylinder away from the box by 5mm (effectively shortening the rod even more but nope, this doesnt help. The cylinder doesnt appear to have any pressure on it when resting.

 

Any ideas?

 

If i push the pistons back in the bores, the hubs turn freely but when i push the pedal a few times, they bind slightly.

I can hear them squeeling when driving!!!!

 

Any help would be greatly appreciated.

Cheers.

[RS2kSX]

when i fitted my willwood kit & bias box i had to cut 3/4" from both master cylinders to allow the pedal to sit level with the clutch, may help?

[sambo]

3/4" !!!

 

Ok mate, thanks, i think i'll pull the pedal box out again and re-evaluate the situation!

[Tom]

I had to fit a return spring to my brake pedal on mine. The weight of the pedal was just enough to rest on the cylinders and cause the brakes to bind slightly. give it a go

[TILBROOK]

I had to fit a return spring to my brake pedal on mine. The weight of the pedal was just enough to rest on the cylinders and cause the brakes to bind slightly. give it a go

 

same on mine i used a rear brake shoe spring, nice and small but strong

[sambo]

I had to fit a return spring to my brake pedal on mine. The weight of the pedal was just enough to rest on the cylinders and cause the brakes to bind slightly. give it a go

 

 

Thread revival, but still not sorted!!

 

Tom, when you discovered that the brake pedal was putting pressure on the cylinders did you find that pulling the pedal up with your feet was enough to release the brakes and stop them binding?

 

I ask because this didnt help with my situation. Even un-bolting the master cylinder and pulling it so that the rod was fully extended didnt release the brakes fully.

 

Any other idea's guys?

[turnover]

you sure the discs arnt warped or you may need to shim the caliper so you have an even gap either side of the disc

[sambo]

the discs and calipers are brand new and not warped

 

the caliper does sit slightly off center to the disc but i spoke to AP about this and said it wont be a problem as long as there is room for expansion. Besides, if this was the issue, my thinking is that the pas with less room would bind only but its both pads on both sides of the car.

 

[turnover]

what brake lines you using,you havnt got one twisted or crushed slightly and its not releasing the pressure

[sambo]

Using hard lines through the car into a bulkhead union through the inner wing to go to the flexi hoses going to the calipers?

Simple enough really!

 

Of course, thats never the case!

[turnover]

so if you undo the flexie i presume they are free

[escort21]

Ive had this when the master cylinder was to large just an idea

[sambo]

so if you undo the flexie i presume they are free

 

 

Nope! i undid the line at the caliper and they still slightly binded.

I will put the box back in tomorrow with the brake pedal sprung.

 

Fingers crossed!

[down2earth]

The cylinder doesnt appear to have any pressure on it when resting.

 

If i push the pistons back in the bores, the hubs turn freely but when i push the pedal a few times, they bind slightly.

 

Whats the history of the master cylinder sambo ie is this new ? This could be sticking !

 

 

Interested to see what occurs when you fit every thing back and then re test with the brake pedal spring mod ?

[sambo]

The master cylinder is a brand new Girling one!

I bought it cos the old was seemed to be slightly sticky.

 

I'll put the box back in today and try and find someone to help me bleed it all and then we'll see what the score is............

[down2earth]

Hi Sam. Not sure if you have resolved things either from a pedal spring or wearing/bedding the brakes in on r/test ?...If its still binding on the fronts or all round and you still have the same symptom even with the new m/c's have you confirmed that the rod's and m/c's are returning correctly by pulling back the rubber boots & looking at the rods after pressing and releasing the pedal to see if the retaining washer/snap rings are not askew or jamming in the m/c's and that the rods are not bent or misaligned, also what size/bore are the m/c's front & back ?

 

 

The other thing it seems you've had a lot of trouble with is the bias adjustment/pedal issues which got me thinking is this all to do with the complete pedal box itself in that it is not designed for the mk1 escort and is infact a mk2 escort type, so I wonder is it a genuine modified mk1 type & if not the adjustment/pedals could be set up differently causing problems with the ratio or was this in when you got it and was ok with other brakes on ? (I see Gartrac have a sale on mk2 pedal boxs but not for the mk1 which is typical if it was needed)

 

 

You could always remove some of the braking system corner by corner and with your pedal box out rig up a bench test to confirm each brake unit is operating correctly and that the bias adjustment is not seizing etc which should determine if the hub/bearing/disc fitment or the caliper spacing/mounting has an alignment issue on the car etc.

 

One other thing how are you bleeding out the brakes do you pressure bleed or is it a mechanical bleed using new fluid Dot 3,4 or 5.1 ?... I take it theres no problems bleeding ie does the pedal come back up if your pumping to bleed and that you have no air bubbles when you lock off each corner ?...It is also possible after applying pressure on/off on the pedal several times a slight vacum has become present in the system somewhere and could limit how the return spring in the m/c comes to its rest just another thought you could look into if the problem continues...

[evil knievel]

Sure its not just something simple like pads sticking in the caliper?

 

I'm not sure what type you have, are they floating calipers? If so check sliders etc. If the pistons are pushing back easily then it wont be a twisted or crushed line/hose, and the calipers themselves aren't sticking. As you said it could be something in the new master cylinder.

[sambo]

Hi chaps, cheers for the replies.

 

After taking the redal box out again i made sure there was free play on both brake cylinders and sorted the pedal so that it returns fully on a spring.

I put it back, bled it all and took it for a spin.

All actually seemed good, the fronts were not squeeling down the road when i wasnt on the brake pedal and they worked really well.

 

However..... it needed a bit more of a bleed so i set about doing this yesterday and wound the bias to the rear, bled it. then i went to wind the bias to the front and it wouldnt turn.

 

It turns out the bias bar thread has got snagged and its trashed the thread!

 

Bloody thing! If its not one thing it's another!!

 

So, i am trying to set the box up in the car which is proving very, very difficult!

We are getting there but i am sick of it at the mo so i am gonna leave it for a few days.