Rear caliper rebuild questions

[ES 1800]

This might be old to many of you, but here goes. I have several questions about rebuilding the rear calipers on my 73 3.0CS with vented rotors.

1. I got rebuild kits FTE RKS4202. Perhaps @Denis1967 has answered the question about the piston seal taking a set, but the new seals look to have a very square profile, making it impossible to get the piston back in by hand, even after liberal coating with brake fluid. The old seal appearS to be tapered toward the outer edge. I put one of the old ones back in and was able to pop the piston in by hand. It is normal to require considerable effort of a C clamp or harbor press to get them in with new seals?

2. Where does one find ATE paste that is compatible with brake fluid?

3.The "bible" indicates that the pistons are to be repositioned at a particular angle, 20 degrees, using (of course) a special piston gauge. What function does that cutout and the angle of insertion
serve???

4. I split the piston halves, and have new O-ring seals. Referring once again to the bible, it cautions to not reuse the "expansion" bolts. Too late. Seems like high temp Loctite should work using original bolts and nuts, right?

Thanks for the help. I f you need advice about a Volvo 1800, I'm your guy.

 

[Thomas76]

Regarding #4. Bolts are designed to be tightened once, they are similar to head bolts. Some people re-use them and do not see problems. Others follow the Bible. I rebuilt 3 years ago and re-used the bolts figuring worst case scenario is a bolt breaks under braking, which would seemingly cause a leak. Not catastrophic.

 

[eriknetherlands]

#3 is purported to reduce breaking /squeeking noises.
The tool isn't that difficult to make though. If you have a post-it, scissors and a ruler you should be fine.

No personal knowledge or experience.

 

[bavbob]

I have used a c-clamp to pop them back in with no issues.

 

[bengal taiga]

I have used a c-clamp to pop them back in with no issues.

Arguably not the best practice, but in a pinch, another (less glamorous) approach involves the use of slip joint pliers and a piece of scrap wood or equivalent to prevent unintended damage to piston/caliper.

 

[deQuincey]

This might be old to many of you, but here goes. I have several questions about rebuilding the rear calipers on my 73 3.0CS with vented rotors.

1. I got rebuild kits FTE RKS4202. Perhaps @Denis1967 has answered the question about the piston seal taking a set, but the new seals look to have a very square profile, making it impossible to get the piston back in by hand, even after liberal coating with brake fluid. The old seal appearS to be tapered toward the outer edge. I put one of the old ones back in and was able to pop the piston in by hand. It is normal to require considerable effort of a C clamp or harbor press to get them in with new seals?

2. Where does one find ATE paste that is compatible with brake fluid?

3.The "bible" indicates that the pistons are to be repositioned at a particular angle, 20 degrees, using (of course) a special piston gauge. What function does that cutout and the angle of insertion
serve???
View attachment 166627

4. I split the piston halves, and have new O-ring seals. Referring once again to the bible, it cautions to not reuse the "expansion" bolts. Too late. Seems like high temp Loctite should work using original bolts and nuts, right?

Thanks for the help. I f you need advice about a Volvo 1800, I'm your guy.

if you are my P1800 guy
i am your e9 guy
always search for dequincey threads

Lan-Front axle, brakes, bearings, wheel hub,...and rear brakes too

so after this happened i have decided to take a deeper look on the front axle system,...

e9coupe.com

 

[ES 1800]

Is there some trick to get the dust boot to seat into the groove (and stay there) so the steel retainer ring can be installed? The piston is extended out of the bore a bit. Should it be pushed in as deeply as possible to get dust boot into the correct position?

 

[deQuincey]

Is there some trick to get the dust boot to seat into the groove (and stay there) so the steel retainer ring can be installed? The piston is extended out of the bore a bit. Should it be pushed in as deeply as possible to get dust boot into the correct position?

You saw my thread on the brakes ?

 

[ES 1800]

@deQuincy, this? Words would help me, such as "Depress pistons into bores and add dust boot and retainer rings.: (if that's accurate.)

Or would this be the way?