glowing rotors

[knudsonm]

I have a problem with my damn S-10 Blazer. The brakes are not confidence inspiring to say the least, yet the front rotors are hot as hell after a longer drive. I came home from the drag strip where they had a hard time slowing the car down from only 110 to hit the return road and then on the drive home the pedal was high and hard. I only touched the brake a few times the whole way home, but they were glowing a dull red after the drive. What is going on here?



The setup is mostly stock. Stock manual master cylinder, with stock pushrod and stock pedal. The prop valve is a new factory replacement. The front rotors are stock with SSBC Force 10 calipers. The rears are 11x2 ford drums. I have Earls stainless brake hoses as well. I also have a Wilwood adjustable prop valve in the rear line.



Hear is how I have it plumbed...

http://i56.photobucket.com/albums/g163/slowride454/DSCN0327.jpg

http://i56.photobucket.com/albums/g163/slowride454/DSCN0321.jpg

do I have the ports mixed up? Is the residual valve on the front brakes possibly? That would definately cause a problem.

[spacecadet]

In the 2nd pic.



The front of the master closetest to the rad is the rear brakes. The one closeste to the firewall is the front brakes. The lines are plumbed correctly into the proprotion valve. The line (in the pic) on the right (1/4 inch fat line) goes to the back brakes. The thin 3/16\'s line that drops closer to the engine should goto a T spliter to both fron wheels.

It appears that you have a twist valve on the front brakes. Remove it and rebleed the brakes. There should be no residul pressure on the front brakes at all.

That valve should be on the rear line.



I\'m sure this will fix the problem.



One other thin, if the rotors got red hot you may need to R&R the rotors and clean & repack the front wheel bearings. Chance are you burned the grease out of them.

Also look at the pads. Chance are they are burnt. They may give very odd braking. They may pull at one time, grab at another or even not stop very well at times. If they are burn I\'d highley suggest replcing them.

Saftey First!!



Thats the brakes!

Space.

[knudsonm]

The lineloc is on the front line and the adjustable prop valve is on the rear line. Do I have the combination valve plumbed correctly?

[grimpuppy]

It is correct from the master cylinder into the combo valve. I believe you have it plumbed backwards comming out of the combo valve.

The port that has the line with the adjust prop valve going to it is for the front brakes. the port that has the line with the line lock on it is for the rear brakes.

[ZZ4Blazer]

The prop vavle isn\'t needed when you have and adjustable one.



Ditch that, or ditch the summit adjustable one.



Front brakes will take the full pressure out of the master with no problems. Just plumb line lock to your front brakes, summit prop to the rear ones.

[knudsonm]

Looks like double dumb-ass on me. I have the ports mixed up on the output side of the combination valve. I wonder how much ET and mph I lost with the front brakes being hung up? Also might contribute to the damn blazer overheating and why the converter was slipping 800rpm at the big end. Time to re-plumb and then R&R the wheel bearings.

[knudsonm]

On 2006-08-17 18:25, ZZ4Blazer wrote:

The prop vavle isn\'t needed when you have and adjustable one.



Ditch that, or ditch the summit adjustable one.



Front brakes will take the full pressure out of the master with no problems. Just plumb line lock to your front brakes, summit prop to the rear ones.





I tried the rear brakes without an additional adjustable prop valve and I did a donut in the street, the 11 x 2 drums are way bigger than the dinky factory drums. I tried running the system without the combination valve and the rear brakes would not work at all, because there was no relief valve or residual valve.

[spacecadet]

You need the proprotion -combination valve because it supposed to hold resdiual pressure on the rear brakes to over come the shoes spring pressure. The 1/4\" line threads in to the hold-off valve. The hold off valve threds into the solid brasss block. This line has to go to the rear brakes.

If you need to lessen the brake pressure than the turn-valve you have will work also in line to the rear brakes.

You can have the line lock on the front brakes if you so choose. But you have to make sure there is NO residual pressure on the front brakes at all.



In the picture, As I stated earlier, the 1/4 fat line goes to the rear brakes. THe thin 3/16 line goes to the front brakes.

[riotpolice75]

get a real good look at the dust boots and seals around the pistons too. with that kinda heat theres a real real good chance one or both the seal and dust boot are shot. if the rubber is warped replace the calipers.







smith

[grimpuppy]

I tried the rear brakes without an additional adjustable prop valve and I did a donut in the street, the 11 x 2 drums are way bigger than the dinky factory drums. I tried running the system without the combination valve and the rear brakes would not work at all, because there was no relief valve or residual valve.





I have the ford 11\" drums on the back of mine and do not run an adjustable prop valve. If the truck did a dougnut you might take a look at the wheel cyclinders if you havn\'t replaced them already. You get the lines switched around the way they are suppose to be and maybe they work a little better.



I bet you scrubbed off a lot of et and mph if your rotors were glowing after the 1/4 run.

[knudsonm]

Well the plumbing problems weren\'t the only issue. I am going to check pushrod endplay. I might even try a set of stock calipers. Could underhood heat be contributing to the problem. I just seems as though the problem gets worse when the engine gets hot (over 200). Or they are unrelated and just both overheat within a mile or so of driving.



More updates when I get home from work

[adh383]

how close are your brake lines to the exhaust? heat may be expanding brake fluid!

[knudsonm]

I checked the pushrod endplay and it is fine. I took the wheels off and you can spin the rotors even after pushing the brake pedal and letting it return, so no residual pressure. I redid the brake lines from the tee to the brake hoses, going under the frame, away from the headers. I started to make up a heat shield, but ran out of daylight.



You should see the red plastic plugs in my wheels. They are all shriveled up and melted to the wheels.

[spacecadet]

Altough the wheels spin Its possible it may have a booster problem.

Drive the truck for a little while. bring back to your place, leave it running. set up truck on jack with a saftey stand. Try to spin the wheel. Again, the truck should still be running.

I say check it this way because I have seen it before where the booster asembly has an issue and the va* suction has actually applied the brakes slighty.

If the wheels are difficult to spin, Shut off truck. Try to turn it again, then pop off the big vacume line going into the booster. Then again...spin the wheel. If its still turns hard then reach inside and pull up on the brake pedal. Spin wheel... If stil an issue, loosen both bolts holding the master to the booster, Then again recheck. If it....Then next open a bleeder, Spin wheel.



Altough it will take a little time and effort to check this way, you will elimante serveral pieces of the brake system from being the casue of your heart ache.



Space.

[knudsonm]

The blazer has a manual master cylinder. I don\'t know if a small booster would fit with tall valve covers on the BBC

[knudsonm]

Hey guys, I\'m not completely nuts!!!



I called up SSBC today for technical support and they said to send the calipers back to Summit, because they don\'t even offer them anymore due to the same problems I\'ve been having.



I\'m going to get some stokers so I can drive it, and send those damn things back.

[ZZ4Blazer]

What calipers? Whatd they say? I\'ve got a set of the aluminum ssbc calipers, and had to pull one off cause it was leaking bad.



If I can return them to summit, for any kinda refund, Id be very happy.

[knudsonm]

They are the Force 10 dual piston calipers. Call up SSBC and tell them you are having problems with the calipers. Doesn\'t hurt to try.



I bolted on a new set of stock calipers and they seem to be better, but still hang a little on the rotors. Does anyone make a return spring for this type of caliper? The only thing I have not replaced with brand new parts is the master cylinder, I wonder if that might help. Even when I really pull up on the pedal the front brakes do not spin as freely as my other cars.

[knudsonm]

www.bowlinggreencustoms.com/shop/customer/product.php?productid=16&cat=84&page=1 (http://www.bowlinggreencustoms.com/shop/customer/product.php?productid=16&cat=84&page=1)



www.chevelles.com/forums/showthread.php?t=19406&highlight=brake+caliper+dra g (http://www.chevelles.com/forums/showthread.php?t=19406&highlight=brake+caliper+dra g)



hmmm....



anyone have experience with this kit?

[ZZ4Blazer]

Hmm, they still have those listed on their website. I might call them anyways. Thanks