Delco Morain Rear Brakes, soft pedal
 

I am at the point where my rear brakes are all back together. Bled them, adjusted them, and all seems to function properly, but I have excessive pedal travel. I am on the fence of what to do next to rectify this.

The background: Car was purchased with a pull to the right when brakes were initially applied that would immediately straighten out. Figuring it was a hose or caliper and I would be bleeding and all... I went ahead and replaced everything up front. New braided hoses, re-manufactured calipers, new rotors, and new bearings/seals. Bled the fronts, went out and bedded them in per Stillen's instructions and all was great, pedal travel was slightly better than it started, pull was gone, and the brakes were a little firmer than when I first got the car.

Then was on to the rears. I didn't replace the calipers as all appeared well, and it just seemed overkill. Confirmed on bench that adjusters worked, parkign brake actuation worked, and no signs of fluid leaks. I replaced the rubber lines with braided, new rotors, and new pads. Got it all back together and adjusted the equalizer bar then started bleeding the brakes. I caught that while I had the hoses disconnected, the reservoir got very low in the front bowl. Filled it up, finished the job while keeping an eye on it. At first, the parking brake only worked on the drivers side. I followed the adjusting procedure working with the actuator screws on the calipers and got to where the parking brake holds on each side and my son stepping on the pedal also stopped me from being able to turn the rotor. I bleed the brakes a lot during all this... just to be sure. I used a vacuum bleeder and then just as a confirmation, had my son help me with the "buddy" method after the car had set for a day or two.

Put it back down on the ground thinking it was time to go bed them in and the pedal just sunk. Doesn't seem to go all the way to the end of travel, but certainly further than what feels safe. Parking brake does work, but I can only say it holds the car on a flat surface at idle and there is resistance in the handle pull. Brakes hold the car. Pedal is very firm with the car off, and when the engine is running it does feel firm once applied (with the excessive travel). I did have the prop valve trip at one point during bleeding and then when I mashed the brake it clicked back and the light went off.

So, should I adjust the equalizer forward a bit more and keep working the parking brake to see if it adjust it.

Should I take the parking brake off again and try to get the adjustment screws to tighten the pads more?

More Bleeding? I started with fluid that looked like Pepsi, what is coming out of the bleeder screws now is definitely clean new fluid with no bubbles.

Bleed with the parking brake actuated? I read somewhere that this style of caliper needs to be bled with it actuate, but didn't see that in any of the Camaro manuals or on here.

I read somewhere that the "Cadillac Style" rear disc brakes require gravity bleeding to actually get the air out (I suppose Cadillac was the first to use this parking brake style), which would be hard to do with a hard line on the drivers side and I didn't see this in any manuals or any notes on here.

Troubleshoot another area of the system?

What's your thoughts? I am too far into this to do a brake swap at this point. Didn't want to invest that much money in a car that isn't seeing track time. This system should be able to get returned to factory operating condition.

Re: Delco Morain Rear Brakes, soft pedal
 

My 1st guess is that the parking brake screws on the calipers need to be tightened up some more. It sounds like the issue is excessive travel. The pads should be just shy of dragging on the rotor...

Re: Delco Morain Rear Brakes, soft pedal
 

Certainly one of the options I am entertaining. Possibly I didn't set enough pre-load against the rotor so when it released there was too much play?

Just to make sure I have this right, the adjustment procedure is to rotate in the direction of operation until it stops (pad against rotor). Then install the 11/16" nut over the 9/16"wrench and rotate in the opposite direction of travel to reset the screw start position and install the lever? The instructions I have say to put a wrench on the screw and install the nut and rotate in the opposite direction of operation to make an adjustment. An adjustment I assume is for a parking brake that is working, but got weaker. It also doesn't specifically say that it has to go flat to flat either. Can the adjustment be done in less than the 60* to go from flat to flat on the screw?

Re: Delco Morain Rear Brakes, soft pedal
 

Kyle, I done mine in a vise....the whole assembly. Rotor, Caliper, and EBrake arm. I set it and then took the whole thing and installed back on car. My brakes are fantastic. As @daferris mentioned....just shy of dragging on rotor

Re: Delco Morain Rear Brakes, soft pedal
 

Also once you get them working what I found works best was to apply the foot brake. Then apply the parking brake before you let off the foot brake. To release the parking brake to the same apply the foot brake 1st (prevents the piston "sticking" on the screw on release.
Most important thing is to use the parking brake EVERYTIME you park the car to keep it adjusted.

Or do like I did when one of my boy's had a '00 Trans Am for a parts car I took the fronts and rears and adapted them to my IROC...
But that's a project for the future... But then my car is my track day toy :)

Re: Delco Morain Rear Brakes, soft pedal
 

Let's hope I don't get to having to remove them again. That sounds like a pretty good idea though. I don't feel like I am pinched for room with it on stands, but It would be nice to not be laying on the ground TBH.

Re: Delco Morain Rear Brakes, soft pedal
 

Yup, had these on my 86 T/A back in High School and learned that. Just never had to do a brake job on them.

So, is the above procedure correct about direction of operation to tighten and then back with the nut installed. I know the screw can suck into the caliper pretty easy without it installed... live and learn. :lmao:

Re: Delco Morain Rear Brakes, soft pedal
 

You had mentioned in your other post where you had problems getting the passenger side caliper bolt out due to the trailing arm....on mine, it was real close and I was able to finagle it out.
I hope you do get them adjusted. It's like night and day stopping now.

Re: Delco Morain Rear Brakes, soft pedal
 

I dropped the LCA, no big issue. One bolt and let it swing down. When it went back up in place it was maybe a 1/2 to a 1/4 of the hole out of line. I was able to put a C Clamp on the mount and inside the LCA and pull it in with almost no force. Bolt went right back in. 18mm head and nut.

Re: Delco Morain Rear Brakes, soft pedal
 

if you figure out how to adjust the emergency brake correctly without removing the caliper please let us know. ive done a complete brake replacement and while the rear brakes are working, i have a low pedal and the emergency brake is not clamping tight enough to keep the car from rolling. i really dont want to remove the calipers again the passenger side was a pain in the butt

Re: Delco Morain Rear Brakes, soft pedal
 

Getting the parking brake working isn't the problem. When I had the calipers off, I used a tool that pushes the cylinder back and bottomed in out. Rotating the adjusting screw bring the cylinder out.

This style does not require the piston to be rotated like the 4th gens (and other styles I have worked on). The haynes manual was pretty accurate in method.

So, the way to do it on the car is to remove the cables, nut, lever, and seals. Use a 9/16" wrench on the adjuster screw and rotate it in the direction of operation until the pads are tight. Based off operation, the more torque you put on the wrench, the better the hold on the rotor.

Now, if you rotate counter to operation direction, the adjuster screw will going in and you will lose your adjustment as the actuation rotation will move the adjuster screw out before it puts force on the pads. So, with the wrench installed (box end) put the 11/16" nut back on. Then rotate counter to operation direction until the 9/16" hex will line up with the lever's hex and have the lever really dang close to its stop when re-installed. I made some marks with a sharpie to help.

Now, I still seem to have excessive pedal travel. I noticed there is a gap between the wrench and the caliper body. Tomorrow, I am going to repeat the above procedure but going to use a washer/screw driver, or other flat object to wedge in that space. To ensure the adjustment screw can't go in at all.

Then I am going to hook back up the parking brake, cycle it and mash the pedal about 30 times, the bleed each caliper again with the parking brake set.

After all that, just want to be clear that there are no issues with getting the parking brake working. This may not be what ultimately solves my pedal travel. If that doesn't work, I am going to plug the outputs of the Master Cylinder individually and Isolate which channel is actually having an issue.

Hope this helps.

Re: Delco Morain Rear Brakes, soft pedal
 

thank you for the detailed info!! hopefully tomorrow i can get out there and try this.

Re: Delco Morain Rear Brakes, soft pedal
 

Sunday, I spent about three hours adjusting the parking brake on these calipers. Once I figured out what I was doing, they are actually pretty easy to adjust. Before they were adjusted, the brake pedal went over half the way to the floor before I got stopping power. Now, with the parking brake adjusted, the brakes start as soon as I tap the pedal. The rear pads are no longer wiggling in the calipers and it only takes about 4 clicks and the parking brake will hold the car in place. I re-bled the brakes just in case, but there was no additional air from the adjustment. So thank you KyleF for the direction, it worked wonderfully.

I also ran across a video on youtube that shows the adjustment process. While the brakes are for a different vehicle, the adjustment is the exact same process. hopefully it will let me post the link.....

Re: Delco Morain Rear Brakes, soft pedal
 

Interesting... the instructions I came across had you install the bolt to prevent the screw from going in. He is doing it differently by allowing the bolt to go in.
Instructions Link
I got mine really close to the actuation point by following what I did above, but still have excessive travel. I am going to try it this way and see if the results change.

Re: Delco Morain Rear Brakes, soft pedal
 

I ended up using a washer as a spacer. Didn't let the screw go back in... and yep... parking brake actuates quickly. Just need to tighten back up the equalizer (which is a PITA). I tried a pass thru socket to make the job easier... yea just as I thought before. Not enough swing on either side to ratchet. It either bangs the torque arm or the driveshaft.

I think the next step I am going to do to hit all suggestions I have read:

Set parking brake, bleed 1 min, top of reservoir, release parking brake, pump brake, cycle parking brake, pump brake, cycle parking brake and leave on, pump brake, and then repeat until I have sent a pint through. If that doesn't ensure I don't have air in the system... I am not sure what the next step will be.

Re: Delco Morain Rear Brakes, soft pedal
 

glad to hear you also got the parking brake adjusted. as far as bleeding goes, i bought two sets of speed bleeders and went throught over a half of gallon of brake fluid before i felt comfortable in there being no air bubbles left. we will see if these brakes self adjust. ive been using the parking brake everytime i drive it.

​​​​​​​btw. yes the cable is a pita to adjust. it took me thirty minutes just to adjust it with open end wrenches turning a small amount each time and flipping/adjusting the wrench

Re: Delco Morain Rear Brakes, soft pedal
 

Yea, I am not sure how people are getting gear wrenches and pass thru sockets/ratchets up there and getting enough swing, I even tried a deep well socket, but it was not deep enough to accept the length of threaded rod I have exposed. I ended up making this out of an old wrench I had laying around:
https://cimg4.ibsrv.net/gimg/www.thi...7bfb8cd94b.jpg


It stayed above the driveshaft and I could get almost a full 180* of rotation. Held the front of the rod with a 9mm open end.

Anyway, got that all tightened up last night, and I have zero doubts about the ability of my parking brake to function. The manual calls for 150lbs of force to take the handle to 14 clicks. I don't know about the actual force measurement, but it is as solid as any parking brake I have ever pulled and 14 clicks isn't easy to achieve, but the levers are fully against their stops when at rest. Rotors freely turn, but I I can here slight girding noises from contact with the pads when I turn them by hand.

Still have crappy pedal travel, I am getting frustrated. At this point, I am sure it is air, and I think air is entering the system somewhere, but I can't find any leaks or fluid on my garage floor. Strange.

I am going to take the bleeder screws out tonight, clean them, and carefully put some Teflon tape around the threads. Should be noted I am vacuum bleeding, not pressure bleeding. Then see how it goes. I think it may not be pulling on the fluid solidly if air is getting around the threads.

Re: Delco Morain Rear Brakes, soft pedal
 

Bled a full pint through each side of the rear with zero change. Still can't find any leaks. I may just bite the bullet tonight and replace the master.

The parking brake starts the grab the rotors at click 2 on the handle, so I can't see that needing any more adjustment. 0 Pad rattle.


Frustrating.

Re: Delco Morain Rear Brakes, soft pedal
 

Re: Delco Morain Rear Brakes, soft pedal
 

Agree with Gremlin. The ONLY way.

Re: Delco Morain Rear Brakes, soft pedal
 

I agree too. I am picking up a kit tonight to make doing it a bit easier.

Hopefully I get time to work in the garage tonight. This weekend I am going to the Ohio State Nebraska Game and taking my kids to see the Grandparents while I am down there. All told, that is about 20 hrs of windshield time for me this weekend. UGH! But, my son has guitar lessons and my daughter has swim lessons tonight so time will be a premium tonight as well.

Re: Delco Morain Rear Brakes, soft pedal
 

I did find the time to get the M/C out and bench bleed it. Unfortunately, I don't know if it was the problem or not. I took it out real quick when I got home. put the plastic fittings in the sides, put it in vise, and then took my son to his lesson. Well, the fittings didn't seal well and when I got home, all the fluid had leaked past the fittings and onto the floor from the reservoir. So, of course when I filled it up and started pumping on it there was plenty of air.

It's been bled and re-installed. Now all I have to do is bleed all 4 corners again and see how that goes. Who knew a dang brake job could be such an adventure.

Re: Delco Morain Rear Brakes, soft pedal
 

So after bench bleeding Thursday night I had a lot of car time (Drove to Southern Ohio) this weekend to think this over. The brake pedal had a bit more pedal travel than I liked when I got the car; I wouldn't know the results until I bled the rears, put the rear back on the ground, and then bled the front.... a lot of time to just find out nothing changed. Plus, I wasn't confident in what I saw with the bleeding tubes. Was it air continuing to come from the Master or was air entering after every pump?

So, I looked up the price of a New Master Cylinder and found it was $45. Yup, replacing a 30 yo master cylinder for $45 bucks seemed worth it after 4 rotors, 2 calipers, bearings, all new pads, and lines. Plus, the new one came with plugs to bench bleed it and leave it plugged off. These would be the plugs I needed to isolate the system anyway. Set the new one up in a vise, filled it, put the plugs and tubes on it, filled it up, waited for some fluid to start dripping out of the fittings, put tubes on fittings and slowly pumped it until I didn't see air bubbles. Then I swapped those out for the fittings that came with it that plug it off. Pumped some more until the piston was firm. The instructions said 1/8" of travel and just couldn't get it there. Seemed like a dead spot and no more air was coming and the piston was solid just a bit past 1/8". I had a short metal rod that I had wrapped a rag on that I was resting against my chest and leaning my body weight against it as well as pushing. I felt pretty confident the air was out.

Installed it, but left both plugs in. Hit the brake pedal and it was like hitting a wall. About a 1/4"-1/2" of free travel, and then hits a wall. I wish that first bit of travel had some building resistance, but I can live it that.

Hooked up the rear channel and bled it. To start, I just put the tubes on and cracked the bleeders open and let gravity do it's thing until the fluid reached the vacuum unit. Then I turned on the vacuum. Both sides at the same time at first. Let it run that way for about 5 minutes, and then gave each side an individual 2 minute bleed starting with the passenger side. Pulled over a pint total. With the front channel still capped, hit the brake pedal. It was still like hitting a wall. FINALLY! I didn't start it and hit it with the booster. I was afraid the nylon plug's threads wouldn't hold in the front channel, but it was noticeably different. So, as I suspected, it wasn't in the adjustment of the rear brakes at this point.

So, now onto the front. Got the front line connected and rear end on the ground. Broke the front lug nuts loose. Next time I get some garage time, I will get it jacked up and bled.

Little tip to save time, loosen the master cylinder to you can wiggle it around to connect the brake lines. Makes it a lot easier than trying to force the lines into position without bending them.

Re: Delco Morain Rear Brakes, soft pedal
 

So glad to hear you're making progress! Yeah, $45 bucks for a MC is great, especially after changing everything that you done so far.
Your brake system will be Top Notch when you're done.

Re: Delco Morain Rear Brakes, soft pedal
 

That was my rational reasoning. I am not one that just likes to throw parts at problems, but after I was sure there wasn't any misadjusment in the rears, it just didn't make sense.

Re: Delco Morain Rear Brakes, soft pedal
 

So are there any updates? I've always felt the pedal was too soft on my car and you'd really have to get on the brakes to stop quickly...locking up them up is almost impossible.

Re: Delco Morain Rear Brakes, soft pedal
 

if your current car is the same as listed in your profile then you have a different rear disc setup then what this topic is about unless you swapped them out.

Re: Delco Morain Rear Brakes, soft pedal
 

No updates, life got busy with work and family, weather turned cold and things needed done around the house. I have since changed out windows, raked leaves, got the snow shovels out... and so on. We have already had lows in the the teens!!!!

Plus some of the frustration of having new pads/rotors on all 4 corners, new front calipers, new master cylinder, new brake hoses, and all new brake fluid still having a squishy pedal has me mentally unmotivated in combination with the weather. Not really itching to drive the IROC right now.

The update is it seems no matter what I do I can't get all the air out.

My next step is to use the nylon plugs that came with the mater cylinder. Disconnect the rear, plug and secure it with a C-Clamp, and then see if I can get firm brakes with just the fronts... Then either continue to address the fronts until I do, or get back to figuring out the rears if the fronts are firm.

Re: Delco Morain Rear Brakes, soft pedal
 

Well, it's about time to get back at it. I started another thread about any suggestions... lots of views, no replies. I will be getting the garage cleaned up this week and be back to working on the cars the following. Probably start with my Vette and get it un-winterized first. Then jump back on the IROC. Any suggestions anyone has for troubleshooting the situation is welcomed.