Newton Posted September 19, 2016 Share Posted September 19, 2016 swapped rear axle for a c 8.25 with disc upgrade also have a xj prop valve with zj internals trying to bleed but can't get any fluid to the rear no matter how much i pump tried gravity no luck starting from the furthest away from the master cylinder fist... is there a different procedure to bleed this setup? Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 19, 2016 Share Posted September 19, 2016 What did you do with the MJ load sensing valve? Bypass it? Link to comment Share on other sites More sharing options...
SBpunk Posted September 19, 2016 Share Posted September 19, 2016 Was just going to post up on this. If you haven't bypassed it maybe Hornbrod or someone can answer. The line labeled "height sensing valve" needs to be plugged correct? After that the line going into the load sensing valve needs to be ran directly into the soft rear brake line? Link to comment Share on other sites More sharing options...
SBpunk Posted September 19, 2016 Share Posted September 19, 2016 Nvm just blocked off... wouldnt make sense putting it into the soft line Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 19, 2016 Share Posted September 19, 2016 Good writeup here: http://comancheclub.com/topic/30325-complete-brake-overhaul/ Link to comment Share on other sites More sharing options...
Eagle Posted September 19, 2016 Share Posted September 19, 2016 Was just going to post up on this. If you haven't bypassed it maybe Hornbrod or someone can answer. The line labeled "height sensing valve" needs to be plugged correct? After that the line going into the load sensing valve needs to be ran directly into the soft rear brake line? Incorrect. However, it doesn't matter. Newton posted that he is using an XJ proportioning valve. I think what's more important is Hornbrod's question as to what (if anything) was done to/with the rear height-sensing valve. Link to comment Share on other sites More sharing options...
SBpunk Posted September 19, 2016 Share Posted September 19, 2016 Was just going to post up on this. If you haven't bypassed it maybe Hornbrod or someone can answer. The line labeled "height sensing valve" needs to be plugged correct? After that the line going into the load sensing valve needs to be ran directly into the soft rear brake line? Incorrect. However, it doesn't matter. Newton posted that he is using an XJ proportioning valve. I think what's more important is Hornbrod's question as to what (if anything) was done to/with the rear height-sensing valve. Damn I'll look into it more. Was hoping it'd be that easy hahahaha Link to comment Share on other sites More sharing options...
Eagle Posted September 19, 2016 Share Posted September 19, 2016 Incorrect. However, it doesn't matter. Newton posted that he is using an XJ proportioning valve. I think what's more important is Hornbrod's question as to what (if anything) was done to/with the rear height-sensing valve. Damn I'll look into it more. Was hoping it'd be that easy hahahaha It is that easy. There are several previous threads discussing it. But you use the rear line out of the "nose" of the MJ splitter block, and you plug the one out of the bottom (labeled "Rear Brakeline" in your illustration). MJ Distribution Block: XJ Proportioning Valve: Link to comment Share on other sites More sharing options...
Newton Posted September 20, 2016 Author Share Posted September 20, 2016 What did you do with the MJ load sensing valve? Bypass it? load sensing valve in the rear was removed can't use the mj load sensing valve with the xj prop valve i don't think ...just can't seem to get fluid to the rear wheels to bleed ..ordered a brake bleeder kit off ebay with vaccuum pump i'm gonna give it a go any other ideas welcome.. Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 20, 2016 Share Posted September 20, 2016 The load sensing valve was removed by whom? If by you, did you also swap in the XJ proportioning valve up front and do the plumbing required for the rear brakes w/o the LS valve? Link to comment Share on other sites More sharing options...
Newton Posted September 20, 2016 Author Share Posted September 20, 2016 The load sensing valve was removed by whom? If by you, did you also swap in the XJ proportioning valve up front and do the plumbing required for the rear brakes w/o the LS valve? I'm sorry if I didn't explain my situation properly..but to answer ur question yes xj valve is up front and necessary plumbing done correctly.. Link to comment Share on other sites More sharing options...
88whitemanche Posted September 21, 2016 Share Posted September 21, 2016 The load sensing valve was removed by whom? If by you, did you also swap in the XJ proportioning valve up front and do the plumbing required for the rear brakes w/o the LS valve?I'm sorry if I didn't explain my situation properly..but to answer ur question yes xj valve is up front and necessary plumbing done correctly..When you put in the zj plunger(internals) in the prop valve did you bleed it? Link to comment Share on other sites More sharing options...
Newton Posted September 21, 2016 Author Share Posted September 21, 2016 The load sensing valve was removed by whom? If by you, did you also swap in the XJ proportioning valve up front and do the plumbing required for the rear brakes w/o the LS valve?I'm sorry if I didn't explain my situation properly..but to answer ur question yes xj valve is up front and necessary plumbing done correctly..When you put in the zj plunger(internals) in the prop valve did you bleed it? No i didnt know i had to bleed it most of information i gather just said g ahead and bleed the brakes as usual did not say i had to bleed the prop valve..is the a write up on how to bleed the prop valve? Link to comment Share on other sites More sharing options...
88whitemanche Posted September 21, 2016 Share Posted September 21, 2016 There's this video...that mentions bleeding it https://youtu.be/fwi2g40ymL0 Link to comment Share on other sites More sharing options...
Newton Posted September 21, 2016 Author Share Posted September 21, 2016 There's this video...that mentions bleeding it https://youtu.be/fwi2g40ymL0 Thanks i'll check it out Link to comment Share on other sites More sharing options...
Eagle Posted September 21, 2016 Share Posted September 21, 2016 The instructions for bleeding the system with the height sensing valve have been posted here multiple times. Link to comment Share on other sites More sharing options...
SBpunk Posted September 21, 2016 Share Posted September 21, 2016 It's a pain. I couldn't ever get it to bleed right. Link to comment Share on other sites More sharing options...
Eagle Posted September 21, 2016 Share Posted September 21, 2016 Wait a minute ... Newton, didn't you post that you replaced the MJ front distribution block with an XJ proportioning valve? The MJ unit has two lines running to the rear, one to the height sensing valve and the other to an emergency bypass circuit. The XJ proportioning valve only has one line to the rear. If you still have the height sensing valve in the rear, that's your problem. You need to run the one line from the front directly to the flex hose at the rear axle. Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 21, 2016 Share Posted September 21, 2016 The load sensing valve was removed by whom? If by you, did you also swap in the XJ proportioning valve up front and do the plumbing required for the rear brakes w/o the LS valve? I'm sorry if I didn't explain my situation properly..but to answer ur question yes xj valve is up front and necessary plumbing done correctly.. Exactly as Eagle stated above. I asked that previously, and the OP's reply is highlighted. So I ASSumed this was done. Maybe not.......... Link to comment Share on other sites More sharing options...
Newton Posted September 21, 2016 Author Share Posted September 21, 2016 The load sensing valve was removed by whom? If by you, did you also swap in the XJ proportioning valve up front and do the plumbing required for the rear brakes w/o the LS valve? I'm sorry if I didn't explain my situation properly..but to answer ur question yes xj valve is up front and necessary plumbing done correctly.. Exactly as Eagle stated above. I asked that previously, and the OP's reply is highlighted. So I ASSumed this was done. Maybe not.......... Wait a minute ... Newton, didn't you post that you replaced the MJ front distribution block with an XJ proportioning valve? The MJ unit has two lines running to the rear, one to the height sensing valve and the other to an emergency bypass circuit. The XJ proportioning valve only has one line to the rear. If you still have the height sensing valve in the rear, that's your problem. You need to run the one line from the front directly to the flex hose at the rear axle. guys there is no height sensing valve in rear... have a single line from the xj prop valve in the fron directly to the flex hose in the rear Link to comment Share on other sites More sharing options...
Eagle Posted September 21, 2016 Share Posted September 21, 2016 guys there is no height sensing valve in rear... have a single line from the xj prop valve in the fron directly to the flex hose in the rear Okay, exactly how are you bleeding the rear brakes? Link to comment Share on other sites More sharing options...
Newton Posted September 21, 2016 Author Share Posted September 21, 2016 have someone pump the brake and hold while i open nipple to release air.. close nipple and repeat.... Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 21, 2016 Share Posted September 21, 2016 Have you tried removing the rear bleed screws and making sure their passages are open and clear? I've had them clog up completely with junk so no fluid could pass by just cracking them open. Link to comment Share on other sites More sharing options...
Eagle Posted September 21, 2016 Share Posted September 21, 2016 have someone pump the brake and hold while i open nipple to release air.. close nipple and repeat.... The way I was taught to do it is for the helper to pump the brakes SLOWLY two or three times, then while the peddle is UP you open the bleeder and the helper depresses the peddle SLOWLY, and holds it down until you have closed the bleeder. Then repeat, until you get clear brake fluid and no bubbles from the bleeder. If the peddle is held down when you open the bleeder, then when the peddle is released it's going to suck air in through the bleeder. You're just fighting yourself. And the helper has to pump the peddle slowly, because rapid pumping just aerates the fluid. Link to comment Share on other sites More sharing options...
Newton Posted September 22, 2016 Author Share Posted September 22, 2016 have someone pump the brake and hold while i open nipple to release air.. close nipple and repeat.... The way I was taught to do it is for the helper to pump the brakes SLOWLY two or three times, then while the peddle is UP you open the bleeder and the helper depresses the peddle SLOWLY, and holds it down until you have closed the bleeder. Then repeat, until you get clear brake fluid and no bubbles from the bleeder. If the peddle is held down when you open the bleeder, then when the peddle is released it's going to suck air in through the bleeder. You're just fighting yourself. And the helper has to pump the peddle slowly, because rapid pumping just aerates the fluid. Kool I'm going to try your method and see if that works Link to comment Share on other sites More sharing options...
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