Df rear calipers

[D&dgoblin69]

I installed the new calipers provided with kit.I can not get them to lockup. I have portioning valve installed. I’ve bled brakes multiple times. I’ve turned piston back In for parking brake then ratchet back out. Bled brakes again. Brake pedal gets hard but only locks the front .I believe the calipers are solstice they have an internal parking brake on the piston. Any thoughts anyone have this problem

 

[LLBenJ]

I had a lot of problems getting my brakes bled. At max rear braking, with proportioning valve, the fronts are still doing most of the work. Make sure you are "nipples up" on those rear brakes.

 

[D&dgoblin69]

I’ve tried portion valve both directions even with pedal to the wall with booster applied I can turn my rear rotors by hand.

 

[Desert Sasqwatch]

When you say both directions, not sure what mean? The valve is a one-way pressure limiter - should have 'IN' and 'OUT' markings, and is installed in the front brake circuit, not the rear. If everything is installed correctly it will not have any effect on the rear braking circuit. If you can turn the rotors by hand with the brake pedal applied there is something incorrect in the rear circuit - air in the lines/calipers or something is either preventing or blocking the pressure from the master cylinder to the rear braking circuit.

 

[D&dgoblin69]

I get it I mention the portioning valve because alot of us have added the portioning valve to give the rear brakes a higher percentage of hydraulic pressure. Yes the portioning valve is tied into the front brake lines. Back to the rear brakes when bleeding fluid comes out the bleeder. Iam leaning towards a faulty master cylinder but the donor colbalt never had this issue I think. My pedal when not running is hard don’t feel it moving under pressure it’s stable. When starting car under booster assist pedal sinks down a bit front brakes are quick to lock up but rears only drag a bit. Almost like ether calipers are not extending enough

 

[D&dgoblin69]

Or master cylinder in the rear hydraulic circuit is faulty. These are solstice calipers with internal mechanical parking brake . I would think if my master cylinder rod is moving internal for the rear circuit I’d see brake reservoir rise because it would be pushing the wrong way

 

[D&dgoblin69]

Went back out to the garage after a dispointing day haha . I want to be out enjoying the hood weather. So I installed the Tilton brake reservoir it has three individual reservoirs. So I got front brake and rear separated and clutch on another. When watching the fluid in reservoir when applying brake pedal front reservoir drops and rear raises and when release pedal fluid goes in reverse. I think what Iam seeing is the rear master cylinder piston has failed. I’ll add video

 

[Rttoys]

Hhmmm. Weird. Thinking.

 

[Desert Sasqwatch]

There is a double seal between the front brake piston and the rear brake piston inside the master cylinder. Sounds like the pressure from the front piston is bleeding into the rear piston when pushing on the brake pedal. Definitely believe you are on the right track.

 

[Joebob]

I don't think this is your problem but found that for the first time driving on new pads and rotors, I had very little braking force until the pads were bedded. For the rears you can drive a bit with the parking brake handle pulled up to create some drag and put some heat cycles into the rear pads which is hard to do under normal braking with these cars. The pistons need to be ratcheted out to meet the rotors as well on a new set up. Again, from the sounds of the fluid transfer, I think it is your master cylinder but somethings also to watch out for on a new system.

Joe

 

[D&dgoblin69]

I can't believe it lol. I took a break from this weekend because of the brakes. Decided tonight I'll go out and got the horn and hazards working can't figure out the Info on the cluster yet. I have alittle brake fluid extra so I'll mess with it. I pump the brakes three times I look in the rear reservoir and fluid drops never rises hum so Iam like we'll now Iam confused thought I had a master cylinder leak but it's holding fluid down.I go to the back rotor it still spins so I crack the bleeder and bam my brakes lock up now. Lol I missed Saturdays perfect weather but at least it's working. I bought a master from rock auto I may send it back. No need for a spare.Iam a mechanic of 25 years and don’t act like it. Hope I didn’t lead anyone astray. I’ll be keeping feel on these brakes if something comes up. My master cylinder has 123,000 miles and had been sitting on the garage floor with no fluid in it while building the kit. The master I ordered is acdelco they use epdm seals like what some of are brake lines are made of especially the hose you can buy on the cheap at tractor supply.

 

[D&dgoblin69]

You must forgive my brake bleeding efforts as well Iam using a wood workers clamp. No secondary person to pump brakes and hold or brake bleeder.

 

[Robinjo]

You really need this.....

Amazon.com

 

[devianteng]

You really need this.....

Amazon.com

Is that something you have and use? I've been looking at this one for a while, just never ordered it.

 

[Rauq]

I'll second the pressure bleeder. I can do all 4 brakes in 10 minutes with it, and the clutch line from the master to the bleeder. Nothing will get the clutch slave without pumping, but the pressure bleeder keeps the clutch line packed with fluid during the process. Vacuum bleeding works but I don't think it's as easy.

 

[Gtstorey]

I use the motive also.

 

[Robinjo]

Is that something you have and use? I've been looking at this one for a while, just never ordered it.

Yes, it makes doing the bleeding jobs easy. A 1 person task except for the TOB bleeding. This won’t be your last brake bleeding so a small investment now will be worth it overall.

 

[D&dgoblin69]

I’ve got one that flushes my dsg double clutch Volkswagen transmission .I leave it for that purpose so I don’t contaminate. I’ll need to take car to work to use their brake bleeder. Yeah bleeding maybe my only problem. I got full brakes now I’ll drive to work and bled and keep a feel for any changes.

 

[devianteng]

Yes, it makes doing the bleeding jobs easy. A 1 person task except for the TOB bleeding. This won’t be your last brake bleeding so a small investment now will be worth it overall.

I use a bleeder bottle to do things now, which has worked well for me so far. I’m sure it’s not perfect, but I’ve never felt I needed more. But I enjoy buying new tools…so…

 

[D&dgoblin69]

So I used a bleeder bottle same thing no rear brakes and fluid starts squirting from rear reservoir to front. I replaced master with a dorman it was even worse . The three chamber Tilton reservoir made diagnosis easy since the brake front and rear brake system is separated individual reservoir. Talked with Chevrolet parts department the ac delco master cylinder is discontinued.anyone have # off the Wilwood master cylinder? What’s required pedals as well?