Brake drag with S-10 brakes

[LOT]

Bear with me as this will be long. I have an 85 with hyd. boost brakes but have converted the engine to 87. I am using an 87 power steering pump and all else is 85. I have the S-10 front brakes. Do not know as to what if any drag I had JUST before the S-10 brakes but I do know that in the past (prior to S-10 brakes) that there was 0 drag or to put it another way is that you could spin the front wheel while off the ground and it would contuine to spin. Now there is always some constant drag. This is what I have done.
Rebuild calipers 2 times my self.
Bought reman. calipers
Installed reman. master cyl.
Installed reman. hyd. boost unit
Installed new braided front brake lines
Had the preportioning valve apart and cleaned
Installed larger 1/4 in front brake lines as the stock is 3/16.
There is NO AIR in system as brakes are great and STOP and HOLD great.
Still drags,doesn't matter whether the engine is running or off. I can take wheel off and using a large screwdriver push piston back some and wheel turns as when it had stock spindles--free. Push brake pedal and the drag is back. I had the rotors trued in August and parked car as we were moving from Central In. to BG. My wife followed me on one trip to BG and drove the car. Once I got time I pull the rotors and sure enough they had hot spots.I ask this once before a year or so ago and never got an answer. So I will ask again "those with S-10 brakes are they FREE"? I am open to any and all suggestions. Thanks for looking.---Lee

 

[regal81455]

? for you - how did you use the 87 steering pump? I thought the hydroboost pumps had three lines where the powermaster/vacuum setups only had two? not sure if this would cause your problems but Im going to be doing this swap ( hydroboost setup ) soon and i have a 86-87 pump but thought I was going to have to go to a hydroboost pump - just curious, pics would be nice too...

TIA

 

[LOT]

answer

? for you - how did you use the 87 steering pump? I thought the hydroboost pumps had three lines where the powermaster/vacuum setups only had two? not sure if this would cause your problems but Im going to be doing this swap ( hydroboost setup ) soon and i have a 86-87 pump but thought I was going to have to go to a hydroboost pump - just curious, pics would be nice too...

TIA

The hyd. boost pump only has 1 pressure line discharging as does the 87 pump. Maybe what you are thinking is the hyd. boost unit has 3 line on it. Pressure in from pump--pressure out to power steering--and a low pressure 3/8 in. return that also goes into power steering resivior as does the return from power steering. I did put another port in the 87 resevior to accomadate the extra return line. My spelling suck and I'm not taking time to look up the correct spelling. As for connecting the 87 pump discharge to the 85 hyd. pressure line going to the hyd. boost unit. I used a Parkin Hanifan 3/8 in. high pressure coupling.

I answered you ? Now tell me what's wrong with my $ pit. Best of luck.--Lee

 

[turbo nasty]

Hey Lee are you sure your guide pins and bushings on the calipers are straight/lubed and in good working order?

 

[LOT]

Thanks

Hey Lee are you sure your guide pins and bushings on the calipers are straight/lubed and in good working order?

Yes, they are. If one wheel was tighter than the other or pads were wearing uneven, I could see one caliper or one piston being the problem but that is not the case. I even use synthetic brake lube on pins and guides. I'm positive they are free.

 

[steve hughes]

Lee . Crack the bleeder on the caliper see if it releases preasure. Maybe the master cylinder is for a drum brake application and has check valves in it. Also mack sure the rod in the hydroboost cylinder is not too long keeping the piston in the master from returning all the way back. Same at the brake pedal make sure it has a little slack in it.

 

[turbo nasty]

Lee . Crack the bleeder on the caliper see if it releases preasure. Maybe the master cylinder is for a drum brake application and has check valves in it. Also mack sure the rod in the hydroboost cylinder is not too long keeping the piston in the master from returning all the way back. Same at the brake pedal make sure it has a little slack in it.

Great advice..... check the bleeders both with the engine running and not

 

[Pittsburghkid]

Also when you rebuilt the calipers you should have installed the pistons dry without any lube.. or so i've read from another thread.

 

[LOT]

Thanks Steve

Lee . Crack the bleeder on the caliper see if it releases preasure. Maybe the master cylinder is for a drum brake application and has check valves in it. Also mack sure the rod in the hydroboost cylinder is not too long keeping the piston in the master from returning all the way back. Same at the brake pedal make sure it has a little slack in it.

Done that already--Crack bleeder but all that comes out is drip (gravity) and it DOES not free the wheel--still got that slight amount of drag. Also with my hyd. boost system there is very little pedal travel before it starts brakeing. So I removed the master cyl. and added a couple washers between it and the hyd. boost unit. Did not free wheels but does alow the pedal to travel a little farther down before brakes apply. Both sides are equal in drag. What does not make any sense is if I get no pressure when cracking the bleeders that would seem to mean that everything up top is good. As I said I rebuilt the original calipers twice and even bought reman. It seems as for what ever they do not want to retract.

 

[LOT]

Thanks for your reply

Also when you rebuilt the calipers you should have installed the pistons dry without any lube.. or so i've read from another thread.

That is why I rebuilt them twice. First time I used lube to insert the pistons into bore. Second time DRY --now I hear that you can use brake fluid. I assume the reman one would be done right. In any case all three trys has yet to yield to desired results.

 

[monteperformanc]

I could be wrong but I thought all disc brakes had some drag. I will try mine tomorrow.

 

[charlief1]

All discs are going to have slight darg Lee but it sounds like you have more than you're supposed to. Do you still have the stock propotioning valve on it? If it's the cast iron one you may need to change it. It could be stuck in one position retaining pressure in the lines.

 

[LOT]

My plan

All discs are going to have slight darg Lee but it sounds like you have more than you're supposed to. Do you still have the stock propotioning valve on it? If it's the cast iron one you may need to change it. It could be stuck in one position retaining pressure in the lines.

Over the weekend I plan on finding my 3000 lb. gage --Tee it in one of the front lines where the flex meets the hard line--apply brakes and see if or how fast the pressure returns to 0. I would think instantly.

 

[LOT]

did not get the 3000 lb. gage

Over the weekend I plan on finding my 3000 lb. gage --Tee it in one of the front lines where the flex meets the hard line--apply brakes and see if or how fast the pressure returns to 0. I would think instantly.

But I did install a 200 lb. gage--had a friend watch gage--applied pedal and run gage to close to 200 psi--release brake and gage instantly return to 0. I'm wondering if my mismatched combo will ever work together. I'll ask again "To those with S-10 brake, do they turn freely." It's a simple yes or no answer.

 

[STP]

Leo, I have Caprice 1LE brakes on the front of my silver car. Not sure if they are the same as the S-10 brakes or not, but I have little to no drag. Don't have alot of dust buildup on the wheels so I know they aren't hanging up...Wish I was closer and we'd swap parts off mine..Your rear brakes work correct? Just ruling out a prop valve issue. I can hook a gauge up to mine if it would help. But if the pressure ran back down to 0, I'd say that isn't the issue. Strange......

 

[LOT]

Scott

Leo, I have Caprice 1LE brakes on the front of my silver car. Not sure if they are the same as the S-10 brakes or not, but I have little to no drag. Don't have alot of dust buildup on the wheels so I know they aren't hanging up...Wish I was closer and we'd swap parts off mine..Your rear brakes work correct? Just ruling out a prop valve issue. I can hook a gauge up to mine if it would help. But if the pressure ran back down to 0, I'd say that isn't the issue. Strange......

Yes, rear brakes work fine--it is very puzzling--I did get the # of a GM engineer who recently retired from the brake department. I am waiting on a return call from him. Probably something simple. Me of little mind is @ the limit of my mental capacity.

 

[charlief1]

Keep us informed Leo. I'd like to know the outcome in case I run into this later.

 

[tonka]

FYI S-10 set up with powermaster, no noticeable change in drag on the front wheels. Could the caliper be holding the pads at an angle to the rotor? What kind of hot spot pattern did you see on the rotors? Any play in the hub bearings?

 

[LOT]

finally

FYI S-10 set up with powermaster, no noticeable change in drag on the front wheels. Could the caliper be holding the pads at an angle to the rotor? What kind of hot spot pattern did you see on the rotors? Any play in the hub bearings?

Thanks for answering my ? So yours are the same then it must be from the fact that I have an 85 hyd. boost and feeding it with an 87 pump plus the 2001 S-10 brakes.

 

[STP]

Leo, did you install the s10 brakes when you did the 87 swap? Or did you install the S10 brakes later (which I think is the case). I wonder, if it's a high pressure issue, if you could restrict the pressure line??

PS..Go to bed, but first wish me a Happy Bday : )