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View Full Version : Wilwood dics wont bleed- no air/fluid



ALLstrokedOUT
06-27-2008, 05:27 PM
Hello everyone, Were almost done with our 70 Duster project, starting to put fluids in things, looking for leaks. I filled up the master cylinder, and after fixing all the leaks we began to bleed the brakes. Unfortunately, thats why im here, The rear brakes are Wilwood 4 piston 12.19" discs that came on the Strange S60 that we ordered, and they will not bleed, or even let fluid go through them. Other than the new discs we also put in:
1) all new hard and soft brake lines
2) new master cylinder that was bench bled
After trying to bleed the right rear disc for 1/2 an hour with no fluid coming out, we decided to take the brake line off of the back of the caliper, and see if its getting any fluid, we took it off there with pressure in the line and, theres almost no air in it, and has good pressure, but it doesnt seem to be going through the caliper to the bleeder on top-Why is this, what are we doing wrong?

andrewb70
06-27-2008, 07:56 PM
Did you bench bleed the MC?

Andrew

ALLstrokedOUT
06-28-2008, 07:07 AM
Did you bench bleed the MC?

Andrew
Yup, i bled the master cylinder. Its getting good, clean fluid all the way back until the calipers.

Today i took off the hard line entering the caliper (and with brake fluid dripping out of the hard line) i put some compressed air in the caliper, with the bleeder out, a puff of brake fluid vapor came out, nothing else. After that i plugged up all the holes (hard line still off to isolate the caliper) as best i could and got out the hand held vaccum pump, and the calipers wont hold a vaccum :confused: maybe it was escaping from where i had the pump pressed in?? b/c its not leaking any fluid at all when attached.

Temporarily forgetting about the vaccum leak, is it possible my new M/C isnt sending enough pressure to the rears to force the fluid in? The rear discs were an afterthought when we purchased the front disc conversion kit that the M/C came with. Does it matter if the Master is for drums in the rear or not?
Please help, any input, im completely stuck, and dont know whats going on...

Vegas69
06-28-2008, 07:16 AM
Will the left rear bleed out? It highly unlikely you would have two bad calipers. If it won't you need to look at your master. What about the proportioning valve? Is it letting enough pressure through.

ALLstrokedOUT
06-28-2008, 07:54 AM
Will the left rear bleed out? It highly unlikely you would have two bad calipers. If it won't you need to look at your master. What about the proportioning valve? Is it letting enough pressure through.
Im afraid it might be the M/C then. The proportioning valve is all the way open at the moment. What could be wrong with the master? If its the pressure it delivers, im fabricating a temporary brake line now to make the front brake resivoir (intended for discs) go to the back to see if that does it, if that works, i guess im getting a new master.

Vegas69
06-28-2008, 11:02 AM
What brand of master cylinder?

ALLstrokedOUT
06-28-2008, 12:14 PM
Wow...i feel stupid... we fixed the problem. the problem was that the brake caliper was not supposed to accept a flare fitting into it, when we threaded it in it stopped facing a solid slab of aluminum. heres a picture. What we needed that Wilwood didnt send was a 1/8th into a 3/16th flare it took 20 mins to bleed the whole car after that, no problems. Thanks everyone for trying to solve this with me
https://static1.pt-content.com/images/pt/2008/06/discproblem-1.jpg

andrewb70
06-29-2008, 04:43 PM
many if not all Wilwood calipers use a 1/8" x 27 NPT fitting on the caliper. Archaic, but oh well. Thanks for posting the resolution to your problem. Make sure to use thread sealer on the fitting that goes into the caliper.

Andrew