Hi All, I have more brake issues despite the numerous threads and some issues I have solved. To recap I have 57 chevy rear end, mustang II front end with pinto brakes, the stock pedal and a dorman M83579 M/C that is a copy of the 68-72 Mustang M/C. I've got a 2psi residual to the front and a 10psi residual to the rear. I removed the internal residual on the M/C going to the front and left anything in there going to the rear. I recently put a brand new M/C, new lines in certain sections, and the 2psi residual for the front and 10psi for the rear. The car was stopping fine the last couple weekends but I took it for a drive last night to test drive after fixing a timing issue on the motor. It was dragging randomly and I could feel the pedal feeling a little stuck and then releasing. In one other instance I felt the car not stop quite as well (but still ok) and the pedal went in a little further. I put the car on jacks and inspected and nothing conclusive and didn't see leaks. The cap from the M/C does leak a little and I took it off and notice when I push the pedal only the rear reservoir squirts. Is that an indication of air in the rear lines? I had put a piece of hose on the clamp to see if it would shove the lid down harder but I still get a little leak from the rear part of the lid. I hear creaking from the rear when I step on the pedal hard with it on jacks. The noise goes away with the drums off. I noticed the rear shoes seem to be separating from the base. Is this likely the creaking noise? This probably doesn't have anything to do with the brakes dragging? The rear wheels are a little hard to spin by hand in general but not totally locked up (when I had the drums and wheels still on and the trans in neutral) Here are some photos: Does anyone have advice on what to check next? I'm wondering if a sticky pedal ***embly or sticky master cylinder or maybe not enough play in the pedal and still engaging the m/c when it returns back to neutral point. Although I tried a couple of times and I dont feel the wheels locked up when I spin by hand on the front when my foot isn't on the pedal, however I only checked this on the front. Should I get a new set of shoes from NAPA (***uming they have them) and maybe even wheel cylinders? I'm hoping to get the brakes resolved soon, then I'm moving and think I'll have a garage and place to work on this for another 6 months to a year but not entirely sure yet. I will drive the car super lightly in that time and then I hope to buy a house again with a garage a year from now.
New shoes for sure. Creaking is probably the shoes rubbing on the backing plates. Totally normal. Do the shoes first. Then test again. If it still gets firm after driving a while, I'd be suspect of the close proximity you had of your exhaust to the lines. I can't remember seeing a new photo showing a lot of clearance there. Might be overheating and the fluid expanding.
Thanks, here is a photo of the solution and I don't think the lines are getting too hot. The lines are not perfectly square but are secured. When I have time in the future I will redo all the lines to an exact length but for the mean time I had used some of the NAPA green bendable line as I needed to get this on the road for my move. I took just a little fluid out (after the photo) on both front and rear reservoir so its a little above half way. It still leaks out the top on the rear and I notice the rear reservoir squirting when I press on the brake pedal moderately hard. The front doesn't seem to squirt.
Should I change the wheel cylinders? I'm not sure if that could cause brake drag ever but it's such a royal pain to take the rear wheels off because of the 57 Chevy rear end width. I don't want to do that for a little while especially since I'm not sure where I'll be living the next 6months to a year. I have a couple more weeks of garage use at my house left.
One thing I'm noticing.. when I disconnect the pedal ***embly from the push rod and clear it out of the way, the pedal does not return back to the non-pushed position, the pedal drops to the floor.. it has a return spring but im not sure if its supposed to make it go back up to the top position as if it wasn't being pressed.. that could be one of the issues...i got the car set up like this already. hmmm
If your pedal is unhooked from the pushrod and the master, it should still be in an upright position. You need a spring that will hold the pedal up, and provide an eighth inch clearance from the pushrod to the piston. At all times.
Thanks the return spring was just in the wrong location to do anything. It's also not enough spring or is old/weak I am going to get two from NAPA (hopefully)
in my experience whenever I replaced a master, I had to bleed complete brake system starting @ the master. My wife on the pedal (she hates this) and i do the dirty work. I don't have a fancy bleeder but this works for me. I break the lines @ the master, @ the prop valve, then@ the wheels- good luck
I have had it happen where the rear shoes will jump the little bumps they ride on , on the backing plate, causing the shoes to bind up to the drum, the springs get weak, new hardware kits are inexpensive and will solve that, washers on the hold on springs can also help add spring pressure, the little bumps the shoes ride on should also be cleaned and a small amount of grease applied to them to allow the shoes to slide easier...probably not the cure all here but may help.
Thanks, I have one question. Last time I had driven the 53' the pedal was sticking.? If a caliper was sticking or a hose had something stuck in it, would the pedal still return to its neutral position or would it stick as well? I think it was an issue with the brake pedal ***embly, etc but am still looking for clues.
If a caliper or shoes stick a bit, your pedal should still return to the top, like I said in my post above. Your spring should pull the pedal back up even if the master cylinder falls off. Usually a small rubber bumper on the bottom side of the floorboard is where the pedal should return to, every time.
The fluid squirting in the MC is just fluid being pushed out of the compensating hole as the cup pushes past the hole. Check to see if the front hole is clear, I.e, the cup should be behind the hole when system is at rest , use a paper clip to sound in the hole, feels metalic, it's OK, feels like rubber, the cup is too far forward. If soft feel, disconnect pedal and recheck.
Thats good news. I put two springs, changed the rubber boot to the correct one (not a bigger one that could bind) and used washers to isolate one of the pivot joints on the one of the links. I bet the pedal ***embly was the issue. I didn't see leaks anywhere except the M/C top lid on the rear.
My '53 is bagged and the m/c mounts to the frame with the pedal coming through the body. When my air suspension is fully deflated the brake pedal rubs the slot that it comes through. I'm guessing that you have experienced just a slight shift with your body mounts or the m/c mount. Clearance the slot that the pedal comes through or remedy the shift and all should return to how it was.
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