1 ton axle conversion. with rear disc

[rebelblazer89]

I have a Dana 60 front and 14 bolt with cadilac calipers. After changing my Mc to a 1 ton mc I know have no pedal pressure. The breaks no engage but not what I think they should. Has anyone else had this problem. If so. Please help. Thanks

 

[waybad1]

Did you swap the lines front to rear at the m/c? You need to let them gravity bleed first, than bleed them as normal. a pressure bleeder works even better

 

[rcpd34]

Are you using a proportioning valve?

 

[herkdriver007]

Did you bleed the brakes? Are you sure the calipers are mounted correctly? Did you run the MC dry when you were trying to bleed the lines?

 

[CGT80]

did you adjust the caddy calipers. Mine had to be adjusted at the parking brake lever so that the pads would rest almost on the rotors. If there is too much space between the pad and rotor, you will use the throw of your brake pedal to move the pads, but they won't clamp down hard enough. The calipers take a lot of fluid volume to work. If you get plenty of brake fluid out of the line when you bleed them, then your adjustment may be off at the caliper. When I first converted my truck to discs, I didn't get much fluid at the rear. One side of my MC was bad and I didn't know it. I replaced the MC and then had a big squirt of fluid from each pump of the pedal.

If you get the adjustment on the calipers too tight, the pads will rub, too hard, all of the time. Your rotors will heat up and smoke after a couple miles of driving. The adjustment is very sensitive and a PITA. People claim that they will self adjust, but mine never did. Maybe my calipers had issues when they were built. I took my caddy calipers off and now I run the calipers from the front of a 3/4 ton 4x4. They are awesome. I don't have a parking brake now, but the caddy calipers didn't hold the truck with the brake set anyway. I need to put my caddy caliper up for sale-maybe someone else will have better luck with the adjustments.

By the way, I highly recommend Powerslot Rotors and Hawk HPS brake pads. I get 60k miles out of a set of pads on my c20 pickup when loaded with tools, boxes, and ladders. They also stop very quickly.

 

[rebelblazer89]

I have bled and adjusted the rear breaks. The pads sit nice and close but not hanging tight to the rigors. I think I am going to buy a pressure bleeder and give that a shot, but I know that is a expensive gamble. You said you could never get yours to work. Was it worth the money and lack of a parking break, to be done with the bs of it all. Let me know. Thanks

 

[blazin' j]

Cgt80, u have a part # for the pads & rotors???

 

[CGT80]

Cgt80, u have a part # for the pads & rotors???

The pads for the caddy calipers are HB103F.590 Hawk Performance. I reused these pads when I put the 3/4 ton 4x4 calipers on my 14bff. There is only a slight difference in size between the two. The hawk web site has the diagrams with exact measurements for each pad. I haven't had any problem running these pads yet.

I think the pad for the front of the 3/4 4x4 is is same as the front pads for my 79c20 with JB7 brakes. For the front of my truck, 2wd, I run HB131F.595.

I think the part numbers have changed since I did my conversion. Powerslot's contact info is here: http://www.powerslot.com/contact_us.php They helped me with part numbers before.

Powerslot has standard rotors and cryogenic treated rotors. I went with the cryo rotors for the front of my truck this time around. They are supposed to be more resistant to warping, but the standard rotors hold up very well also. You will need the rotors from the front of a 73-87 3/4 ton 4x4 IIRC. I look for brake parts made for the JB7 system, which is 13" x 2.5" rear drums, from what I remember. This is the heavy duty brake option, which came on my truck (camper special C20-8200 GVW).

The calipers will be either for the front of the same 3/4 ton 4x4, or a 76-78 Cadillac Eldorado-rear calipers with parking brake. The 4x4 calipers take a different brake line than the cadilac. For my rear brakes with 4x4 calipers I used the lines from the front of a 79C20 with JB7 brakes (same as the front of my truck) and I removed the metal brackets that were clamped on the rubber lines. The lines for my caddy calipers came in a kit, so I don't know what they were.