gibbon Posted March 2 Share Posted March 2 I've been struggling with the rear brakes on the starion locking on for some time now, its definitely w hydraulic issue, and as the brakes ease off if I crack ANY connection in the system, I think it's an issue with the master cylinder? I disconnected the pushrod from the brake pedal and made sure the piston was being allowed to return fully, so that's all good. The master has residual pressure valves in it which is apparently strange for a disc rear, can I remove them? I cleaned out the return port in the master cyl reservoir and it seemed to work fine on the bench but the moment I reinstalled it, it started giving shit again. Not sure if the port is blocked again, it looks as big from the top as the feed port but I could only get a .010" bit of wire through it in the end, not sure if it tapers or it's just loaded with crud. what would happen if I opened it out? Quote Link to comment Share on other sites More sharing options...
Bling Posted March 2 Share Posted March 2 How many lines running to the rear? I would whip all of the fittings off and give them a good clean out. I'm guessing you have given the whole system a good flush? Quote Link to comment Share on other sites More sharing options...
gibbon Posted March 2 Author Share Posted March 2 I haven't really done much of anything in terms of flushing it out, I just figured that if there was a blockage further downstream, then cracking the line at the master wouldn't have released the pressure? The front half of the reservoir tees off to the front brakes and they're fine. The rear section has a single line, must tee off somewhere under the guts Quote Link to comment Share on other sites More sharing options...
Bling Posted March 2 Share Posted March 2 No idea what the issue is, but i'd at least start with a flush and see how much crud comes out. I've had multiple rear brake balance problems in the past and the specs of dirt in the proportioning valves that caused it were pretty small. Doesn't sound like you have that valve, but i'm just mentioning it as it build up caused lots of headaches. So any build up could be contributing. Someone else will have had this issue before and comment i'm sure. But with old shit, and lack of fluid changes, build up occurs and can cause issues. Just something to start with anyway. I think the cars I had issues with were split diagonally for braking. Current old cars have a tee on the diff to split the single line from front. If no crud in the line to the rear and no build up in the rear tee (could be worth whipping off and cleaning out). Then yeah I guess something is up with master as that is the only other part in the system. Quote Link to comment Share on other sites More sharing options...
tortron Posted March 2 Share Posted March 2 Old rubber lines swell up inside and act like a 1 way valve. I had this on the rear line on thr morrie, was letting the rears stuck on 3 Quote Link to comment Share on other sites More sharing options...
bigfoot Posted March 2 Share Posted March 2 Remove the residual pressure valves for discs, had the same problem on the lancer with a USDM master cylinder 1 Quote Link to comment Share on other sites More sharing options...
cletus Posted March 2 Share Posted March 2 Yeah good place to start, I've got a drum mc on my car and it had an issue with the brakes staying on slightly, popped the residual pressure valves out and smoooooth sailing after that 1 Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted March 2 Share Posted March 2 i had the same problem on my car with the front disk brakes locking on. id put a master cylinder in that had residual valves on both circuits. i removed them and it made it better but the other problem was the pushrod that circlips into the master was too long inside and even full released was actually holding a bit of pressure. more of a side effect of using a Datsun master on a toyota but you may have a similar issue to check for. Quote Link to comment Share on other sites More sharing options...
gibbon Posted March 2 Author Share Posted March 2 ok I've removed the residual pressure valve for the rear circuit but unfortunately that hasn't changed anything. Im thinking there might be a mechanical drag as well though as even with the lines cracked it's not exactly free spinning. I've just re-kitted the calipers and the pins are nice and greased, really don't want to get back in there I'll replace the rear lines and give it a flush too because why not Quote Link to comment Share on other sites More sharing options...
gibbon Posted March 2 Author Share Posted March 2 the throttle is now completely jammed shut and won't budge, god this car is such a fucking diva 1 1 Quote Link to comment Share on other sites More sharing options...
cletus Posted March 3 Share Posted March 3 Are you storing it in the ocean? 2 1 Quote Link to comment Share on other sites More sharing options...
gibbon Posted March 3 Author Share Posted March 3 it's pickled in brine, is this likely to cause issues? 1 Quote Link to comment Share on other sites More sharing options...
Bling Posted March 3 Share Posted March 3 I flushed my lines to death when I had my rear brakes rebuilt. There was a lot of gunk hiding in there so for the effort involved, it was well worth it. Quote Link to comment Share on other sites More sharing options...
bigfoot Posted March 3 Share Posted March 3 4 hours ago, gibbon said: the throttle is now completely jammed shut and won't budge, god this car is such a fucking diva I have a complete dash motor and just about every wire from a gsrx sigma taking up room in my sheds. Also have some starion front caliper kits if you want to give them a go Quote Link to comment Share on other sites More sharing options...
gibbon Posted March 17 Author Share Posted March 17 On 03/03/2024 at 16:37, bigfoot said: I have a complete dash motor and just about every wire from a gsrx sigma taking up room in my sheds. Also have some starion front caliper kits if you want to give them a go man I think I've got real problems now, the bottom end is locked solid, I think I've disturbed the throttle body at some point and it's dumped the contents of the coolant jacket into the inlet manifold/cylinders. borescope tomorrow, FML 2 Quote Link to comment Share on other sites More sharing options...
shizzl Posted March 17 Share Posted March 17 If you have a booster on the brakes, disconnect it , plug the hoses and test it. ive had issues with mine dragging, locking on , then pedal goes to the floor. No leaks. I’ve pin pointed it to a valve inside the remote slave jobby. on the list to go in the bin. Just need a flare tool to fit the new unit. Quote Link to comment Share on other sites More sharing options...
gibbon Posted March 23 Author Share Posted March 23 meanwhile in the cylinder bores 1 1 1 Quote Link to comment Share on other sites More sharing options...
gibbon Posted March 23 Author Share Posted March 23 the red is ATF floating uselessly on a layer of water I guess 1 3 Quote Link to comment Share on other sites More sharing options...
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