68spitty Posted June 7, 2011 Share Posted June 7, 2011 Hi allI have been refurbishing the front disc brakes and I managed to get the first piston done OK, but the second one is not going so good. I cannot get the rubber cover to stay on while I get the circlip over it. Does anyone have some tips or tricks to getting it on. I was lulled into a false sense of security when the first one slipped on with no trouble, but now!!!!Any ideas much appreciated Link to comment Share on other sites More sharing options...
Chambers Posted June 7, 2011 Share Posted June 7, 2011 When I did min I struggled on and struggled on then realised if I got the other half to hold the back half of the clip down against the rubber at the rear I could use some needle nose pliers to position the two ends of the clip at the front. Hope this makes sense Link to comment Share on other sites More sharing options...
68spitty Posted June 8, 2011 Author Share Posted June 8, 2011 Ta RichardI'll have a go with the needle nosed, circlip pliers seemed the way to go - but no luck.4 hands may be a help tooatbKeithPS I assume the "other half" is the second pair of hands? :K) Link to comment Share on other sites More sharing options...
68spitty Posted June 11, 2011 Author Share Posted June 11, 2011 OKI now have the rubber dust covers on and all seemed to be going fine.I have done brakes before and bleeding is usually a simple, if time consuming business 8)EXCEPT THIS TIME -- I cannot get the spongy feel out of the pedal. I tried doing the bleeding as I have in the past - starting at the furthest wheel. Got air out as expected, but after doing all wheels, no air any more but still spongy.I thought there may be air right back at the master cylinder, so I loosened all wheel valves off and pushed down quickly on the brake pedal, but now it's even worse.I had left the system without fluid much longer then normal while I mucked around with the dust covers, so maybe that has caused the problem......I noticed a funny gadget on the brake line junction (see attached image) and I cannot find any reference to it in my workshop manual. Does anyone know if this can be used to bleed air as I can't see any obvious function for it?Has anyone else had a similar problem and if so, solutions much appreciatedregardsKeith Link to comment Share on other sites More sharing options...
mikeyb Posted June 11, 2011 Share Posted June 11, 2011 No, that "funny thing" is just a union that links the master cyl with the pipes that go to each caliper and to the rear. The nut in your photo just attaches it to a bracket on top of the chassis rail!I have had this problem myself, assuming the master cyl, front calipers/rear wheel cyls are all working freely as they should, your problem is most likely air in the rear cyls.You will struggle to bleed them fully unless you first disconnect the handbrake cable from each side then adjust the brake shoes as per the manual (err on the side of being a little tight). Then with the handbrake still disconnected, try bleeding again and you should get a nice firm pedal. Link to comment Share on other sites More sharing options...
68spitty Posted June 14, 2011 Author Share Posted June 14, 2011 I have now bled two whole bottles of brake fluid through the system. The pedal is STILL going straight to the floor ( I have put a block of wood underneath so it doesn't go all the way).I was getting a thin stream of bubbles out of the rear cylinders (the shoes have been adjusted tight against the drum and the handbrake cables are removed) with the occasional bigger rice grain sized bubble, but two pumps have been air-free before I went to the other side.The front brakes gave no air after a number of pumps, so when I got into the car, after removing my helper I was expecting a firm pedal, but it felt like one of the bleed nipples was completely open. I cannot see any fluid leaking anywhere!I just realised I haven't done a disc&shoe setup before, so is two bottles not too much????I'm not sure where to go with this, as the pads appear to be moving okay -- they tighten up on the disc when the pedal is pushed with all bleeders tight. The rear shoes I can't tell yet as they are locked tight, but I didn't touch them and they appeared to be working fine before I started on the front.I'm happy to keep pushing fluid through the system, but am wondering if there's something I need to check first Link to comment Share on other sites More sharing options...
lancepar Posted June 14, 2011 Share Posted June 14, 2011 Quote:The pedal is STILL going straight to the floor ( I have put a block of wood underneath so it doesn't go all the way).I don't know what to suggest, but curious as to why the block of wood in this position? 8) Link to comment Share on other sites More sharing options...
Paudman Posted June 14, 2011 Share Posted June 14, 2011 you may just have the bleed nipple unscrewed too far, and the air is coming through the rear of it. Badly adjusted rear brakes will also give you a spongy feel, even if there is no air in the system. Link to comment Share on other sites More sharing options...
68spitty Posted June 14, 2011 Author Share Posted June 14, 2011 The block of wood was suggested elsewhere so that the MC piston didn't move into an area of the bore where gunge may have collected.I'm only undoing the bleed nipple about 1/3 of a turn (2 flats), but I'll have a go at just cracking the seal. I'm tightening it up and loosening it off on each stroke alsoI had a look on a Chevy forum and there seems to be a need to bleed the master cylinder on the bench.Guess I've been lucky in the past as I've not ever done that before, but if all else fails -- follow anothers successful advice.Will keep you posted -- especially if I ever get it right :-/ Link to comment Share on other sites More sharing options...
thescrapman Posted June 14, 2011 Share Posted June 14, 2011 1/3rd of a turn should be fine.If you want to prove if front or back or both are causing issues, and you have rubber flexible hoses rather than braided ones, clamp off the hoses and see if still spongey. with all 4 clamped it will obviously be rock hard.Other option is to make up short sealed pipes and substitute for the flexible pipes.CheersColin Link to comment Share on other sites More sharing options...
Steve Cureton Posted June 14, 2011 Share Posted June 14, 2011 Most likely culprit is failed master cylinder seals, or if you have already changed them then you have probably got the seal the wrong way round. Link to comment Share on other sites More sharing options...
68spitty Posted June 14, 2011 Author Share Posted June 14, 2011 Hi allI put a service kit through the master cylinders about 12 months ago, they were fine until I just did the front calipers. I'm thinking it's worth while pulling the MC off and checking it, as well as bleeding it before I put it back on.I'll try the clamping of the hoses first but I'm thinking new hose time if they split, so I'll check on availability before I beginta for your thoughtsKeith Link to comment Share on other sites More sharing options...
Nick Moore Posted June 15, 2011 Share Posted June 15, 2011 I'm not sure it's possible to bleed the master cylinder on the bench - could be wrong, but it sounds like a messy process. Link to comment Share on other sites More sharing options...
68spitty Posted June 15, 2011 Author Share Posted June 15, 2011 I didn't clamp the hoses as I didn't have any suitable dowel or clamps and the mention of my attempt when reassembling the MC seemed to ring loud warning bells. I've just had the MC apart and the rubber is in the correct way and when I pressed the plunger, it forced fluid out past the bolt thread I had used to block the outlet hole for assembling, so I assume the pressure is OK as well.I am now thinking that I just need to keep at it, though I did prime the MC before putting it back in, so maybe that's all I needed.I am opening and closing the bleed valve on each stroke when bleeding, and there is a thin stream of bubbles, although eventually there are no bubbles at all, I then do two more pumps to make sure and move onto the next. I tried the pumping up and quick release and tighten suggested by the Chevy site, but still no useful pedal pressure.Anyone want to get some shares in a brake fluid manufacturing company should do so tonight, as tomorrow I'll be at it again :'(PS and yes Nick it is messy Link to comment Share on other sites More sharing options...
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