Brake help for Esprit S3 1985

[Brammy73]

I have had both rear callipers re conditioned and put on the car. The car went in for its MOT and failed on the rear pasenger side break binding on. I sent the calliper back and got a replacement which we fitted and went back for a re test and it has done the same but now both rear callipers are not returning and binding the pads on the disks. I have cracked the bleed nipples on the callipers and this does not release them and I have cracked the pipe at the reservoir and this does not release them, there was no pressure build up either. Could it be three faulty callipers or am I missing something??? Front breaks are fine.

All suggestions welcome

[andydclements]

Cables nice and free?

[Brammy73]

Yes cables free.

Thinking the master cylinder?

[andydclements]

If it was master cylinder (or anywhere up the line from the calipers) freeing off the bleed nipple should ave released it. It does point to calipers themselves. Free off the bleed nipple, ease the pads off using a lever, then apply and compare the force to lever the pads back when the nipple is closed. If it feels the same, then it's not the hydraulics.

[Brammy73]

will give that a try thank you

[silverfrost]

Also check the pads are free moving as the pads sit in the bracket housing iirc,  remove the calliper and make sure the move freely,  if needed,  scrape the flat surface with sharp flat bladed screwdriver and apply a small amount of copper slip to the part of the brake pad that has contact with the calliper mount bracket. 

Could be many things though without havin a look,  First of all try static operation to see what is going on,  to be honest it should not be that hard to see hopefully. 

[ekwan]

Both sides......sounds like a handbrake cable issue unless you are so fortunate to have both calipers seized at the same time.

[jonwat]

12 hours ago, andydclements said:

Free off the bleed nipple, ease the pads off using a lever, then apply and compare the force to lever the pads back when the nipple is closed. If it feels the same, then it's not the hydraulics.

The rear calipers have a ratchet mechanism inside for the handbrake & the piston needs to be screwed back into  the caliper. 

[C43]

I don't think you screw it back. If they are the same as on my 84 turbo then you rotate the piston by 45 deg (there is a slot in the piston to allow a large screwdriver to fit) then push the piston back. Once pushed back you rotate it back the 45 deg to engage on the hand brake assembly. I must admit I agree with Eric, seems strange for both to seize at the same time, very odd. I also agree that probably not the master cylinder but can't be totally ruled out.

cheers

C43

[jonwat]

2 hours ago, C43 said:

I don't think you screw it back.

Later ones you do. The easiest way to tell between earlier & later types is if the handbrake lever can be folded back down after application to save you tripping over it as you exit the car. 

[andydclements]

Whether ratchet mechanism or not, bot types have to allow the piston to retract enough to free-off from the disc.

[Brammy73]

On 03/05/2019 at 08:56, C43 said:

I don't think you screw it back. If they are the same as on my 84 turbo then you rotate the piston by 45 deg (there is a slot in the piston to allow a large screwdriver to fit) then push the piston back. Once pushed back you rotate it back the 45 deg to engage on the hand brake assembly. I must admit I agree with Eric, seems strange for both to seize at the same time, very odd. I also agree that probably not the master cylinder but can't be totally ruled out.

cheers

C43

Hi, thanks for the details... can I ask about your description. You say after winding the piston in you rotate it back 45deg? is there a marker on the piston to say which direction it should be in as I thought these adjust themselves whichever direction the slot is in?

[C43]

On 03/05/2019 at 11:38, jonwat said:

Later ones you do. The easiest way to tell between earlier & later types is if the handbrake lever can be folded back down after application to save you tripping over it as you exit the car. 

 

[C43]

21 hours ago, Brammy73 said:

Hi, thanks for the details... can I ask about your description. You say after winding the piston in you rotate it back 45deg? is there a marker on the piston to say which direction it should be in as I thought these adjust themselves whichever direction the slot is in?

basically you follow the instructions in the manual for replacing rear pads.

1. Remove the two self locking screws securing the caliper body to the two guid pins, whilst holding the guide pins stationary with a spanner to prevent damage to their dust covers.

2. Remove the caliper body and support to avoid straining the flexible hose. Remove the pads and clean the pad abutment areas taking care not to damage the guide pin or piston dust covers.

3. Before fitting the new pads, the pistons must be pushed back into the caliper body and the handbrake auto adjustment mechanism reset. Fit a screwdriver against the end of the pistone and turn the piston 45 deg to disengage the adjustment ratchet. Press back the piston (take care that the fluid reservoir does not overflow), and then return the piston back 45 deg to re engage the ratchet. The slot in the piston should finish pointing at the centre of the disc (but tell the truth it does not matter which way the slot finishes, either pointing to the centre of the disc or parallel to the disc mounting bolts). If unsure post a picture and I will check it out. 

by pushing the piston back you should create enough room to allow the pads to clear the disc. You should not need to open the bleed nipple or any other part of hydraulics to allow the piston to be pushed back. If you do have to it suggests the fluid is not return correctly. The only times I have seen this in the past it has been because the brake pedal is holding the brakes on slightly and the master cylinder piston is not returning. If the master cylinder does not return correctly it holds the reservoir closed and the brakes stay on. 

good luck

C43

[Brammy73]

1 hour ago, C43 said:

basically you follow the instructions in the manual for replacing rear pads.

1. Remove the two self locking screws securing the caliper body to the two guid pins, whilst holding the guide pins stationary with a spanner to prevent damage to their dust covers.

2. Remove the caliper body and support to avoid straining the flexible hose. Remove the pads and clean the pad abutment areas taking care not to damage the guide pin or piston dust covers.

3. Before fitting the new pads, the pistons must be pushed back into the caliper body and the handbrake auto adjustment mechanism reset. Fit a screwdriver against the end of the pistone and turn the piston 45 deg to disengage the adjustment ratchet. Press back the piston (take care that the fluid reservoir does not overflow), and then return the piston back 45 deg to re engage the ratchet. The slot in the piston should finish pointing at the centre of the disc (but tell the truth it does not matter which way the slot finishes, either pointing to the centre of the disc or parallel to the disc mounting bolts). If unsure post a picture and I will check it out. 

by pushing the piston back you should create enough room to allow the pads to clear the disc. You should not need to open the bleed nipple or any other part of hydraulics to allow the piston to be pushed back. If you do have to it suggests the fluid is not return correctly. The only times I have seen this in the past it has been because the brake pedal is holding the brakes on slightly and the master cylinder piston is not returning. If the master cylinder does not return correctly it holds the reservoir closed and the brakes stay on. 

good luck

C43

Great thank you for this, I am going to tackle it this week and will let you know what we find but I agree that it seams to be the fluid returning. 

[82s3]

Try replacing the flexible hoses?

B

[Steve V8]

Who reconditioned the Calipers?

[Brammy73]

7 hours ago, Steve V8 said:

Who reconditioned the Calipers?

SJ Sports Cars

[ekwan]

20 hours ago, 82s3 said:

Try replacing the flexible hoses?

B

Yes. I forgot to mention this too. I had a car that was laid up for 30 years. The insides of the rubber hoses had swollen, so I couldn't bleed the brakes. 

[Brammy73]

5 minutes ago, ekwan said:

Yes. I forgot to mention this too. I had a car that was laid up for 30 years. The insides of the rubber hoses had swollen, so I couldn't bleed the brakes. 

Yes ordered new hoses and should be with me tomorrow.

[ekwan]

3 minutes ago, Brammy73 said:

Yes ordered new hoses and should be with me tomorrow.

My car's very human like. Living a sedentary, couch potato lifestyle resulted in clogged arteries. 🤣

[Gis]

Absolutely. So regular exercise is needed. Careful with gradually increasing loads & thorough warm up/stretching too, to minimise the risk of a sudden heart attack at that age, huh? A form of Lotus yoga, but for the car 😉

[Andyww]

On 06/05/2019 at 08:31, C43 said:

 The slot in the piston should finish pointing at the centre of the disc (but tell the truth it does not matter which way the slot finishes, either pointing to the centre of the disc or parallel to the disc mounting bolts). If unsure post a picture and I will check it out. 

 

The position of the slot does matter as a raised lug on the back of the pads engages with it to prevent the piston turning by itself and disengaging the handbrake mechanism. 

The problem definitely sounds like handbrake cable is too tight or binding. It must have some slack and be completely free to move when released otherwise the ratchet will be engaged all the time and keep forcing the pads against the disc. 

[C43]

thanks Andy, I had forgotten that.

[Brammy73]

Hi All

Update on this is good and we are all sorted... my uncles (both mechanics) came over to diagnose this with me. It was handbrake related and at some point the adjusters by the drivers seat have been set really unevenly so we think when it went in for the MOT they have pulled the handbrake on really hard to try and get both to bite and it has done exactly what Andy WW said it would. Anyway we have stripped it all down, reset the callipers, new hoses and re adjusted the handbrake and all is good in the world again.

Thank you all for advice, very helpful and I know a lot more about my brakes.