Yeah that’s what I’m thinking now. I’ll try the method for measuring it that just send it posted. Pressing the pushrod in is a pain in the *** while the MC is on the car though
Rear brakes are not bleeding.
- Thread starter DentalDart
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Yeah that’s what I’m thinking now. I’ll try the method for measuring it that just send it posted. Pressing the pushrod in is a pain in the *** while the MC is on the car though
Just Send It
There goes the neighborhood!
Yep. It's going to suck when it's filled. I've been there, bud.
That's why I set the pedals up dry before I pressurize the system. It's a ***** to do afterwards. I've learned the hard way.
Dartsun
Mopar Dude
Throw the rear drums back on and call it good lol.
The rears were tight last night, the fronts were trash lol. My problem with the rear drums is I had to bleed the brakes every month or so because the pedal always went soft after a while. I also never had an emergency brake.
Honestly the one huge problem I’ve had with this car for the 7 years I’ve owned it is the brake system.
My wife just tells me to get a “finished one” that I can still drive around and then it doesn’t matter if I tinker with these ones and they are down for a bit. I’m still upset I didn’t get the Vert from @72bluNblu. I found an automatic convertible that I like, but haven’t found a manual convertible.
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Today.
Tried to plug the front port and press the pedal to see if it’s the front or rear brakes where the problem was… well that was a mistake. Right when my son pressed the pedal, fluid just came straight out of the plugged port
Well then I figured I had to bleed the MC again, which would also let me make sure the rod is the correct length. Pushrod was about .25in to long, well compared to the other pushrod in the old MC. So I adjusted that and colored it with sharpie, but sharpie wipes off when brake fluid gets on it so I put some electrical tape around the rod and rebled everything.
I’ll hook it up in a bit, I have contractors coming to my house right now. How much is a brake bleed job? 500 bucks? I’d pay that in a heart beat to get these stupid things working.
Tried to plug the front port and press the pedal to see if it’s the front or rear brakes where the problem was… well that was a mistake. Right when my son pressed the pedal, fluid just came straight out of the plugged port
Well then I figured I had to bleed the MC again, which would also let me make sure the rod is the correct length. Pushrod was about .25in to long, well compared to the other pushrod in the old MC. So I adjusted that and colored it with sharpie, but sharpie wipes off when brake fluid gets on it so I put some electrical tape around the rod and rebled everything.
I’ll hook it up in a bit, I have contractors coming to my house right now. How much is a brake bleed job? 500 bucks? I’d pay that in a heart beat to get these stupid things working.
Dartsun
Mopar Dude
I feel for ya doc, wish I was closer to help you out. Ive never seen such trouble before. I'd almost just scrap all the parts and just start new. As much time you and your son have put into it.
This isn’t rocket science I swear, but it makes me feel like the biggest idiot ever. Need some teeth? I got you, need your brakes bled? Don’t ask me for help
Ok, **** this car?
The pushrod was correct length on the vice, but I’m assuming now that it is on the car, because you have the firewall and the adapter in the way, I don’t think the pedal pushes the pushrod all the way in. It needs to be adjusted longer now.
I did everything right, hooked it all back up correctly and then when going to bleed the brakes (because the MC was off the car) the pedal went rock hard and wouldn’t move anymore after 3 pumps.
The pushrod was correct length on the vice, but I’m assuming now that it is on the car, because you have the firewall and the adapter in the way, I don’t think the pedal pushes the pushrod all the way in. It needs to be adjusted longer now.
I did everything right, hooked it all back up correctly and then when going to bleed the brakes (because the MC was off the car) the pedal went rock hard and wouldn’t move anymore after 3 pumps.
I grabbed the new rear disc brake kit with bleeder screws in the proper 11-12 O’clock position and the proper rear line location on the housing with the distribution block.
Now we will see if…
1. If it was the fault of the mis-match old part's on the car
Or
2. If it was a mis-match of old car with idiot working on old car…
Now we will see if…
1. If it was the fault of the mis-match old part's on the car
Or
2. If it was a mis-match of old car with idiot working on old car…
Just Send It
There goes the neighborhood!
When you assembled the distribution block, how far did the Switch screw inside of the housing? Any chance that it's too deep and is obstructing the fluid path to the rears?
This thing has got me stumped. Especially the hard peddle. That tells me that fluid is being hung up somewhere.
This thing has got me stumped. Especially the hard peddle. That tells me that fluid is being hung up somewhere.
You should be able to use the original factory length for the brake pushrod. I know I run the DoctorDiff mastercylinder and adapter with a factory manual brake push rod in my Duster.
I thought of the switch being an issue, but honestly I didn’t screw it in or unscrew it.
The only thing I can think of at this point is - the old car used an old GM type distribution/proportioning block/valve without a mopar style distribution block on the 8.75 housing.
I’m using a mopar 4 wheel disc brake block without using anything on the 8.75 housing still. So maybe fluid isn’t flowing to all 4 corners evenly? Or maybe it needed the GM style proportioning valve to do the rear brakes correctly.
Problems like this is exactly why you see cars and tractors sitting in fields and barns to rot… something couldn’t be fixed or didn’t have the time and the thing was left to sit for the rest of time
I thought of using my stock one, but I don’t have an extra one of those fancy grommets for the pushrod… so unless I do a half *** o-ring retainer grommet thing like I did before I have to use the one I already stuck in the MC lol. I know you can pull them out, but…. I’m weak as **** and couldn’t get it out earlier today
I thought of using my stock one, but I don’t have an extra one of those fancy grommets for the pushrod… so unless I do a half *** o-ring retainer grommet thing like I did before I have to use the one I already stuck in the MC lol. I know you can pull them out, but…. I’m weak as **** and couldn’t get it out earlier today
I mean, for testing purposes you don't need the rubber grommet thing on there. Just using it to measure the adjustable push rod would be helpful, and even installing it on the pedal and seeing if that changes how the MC pumps up or not would be helpful. You don't need the rubber grommet for that, just don't leave it out when you get the car on the road!
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I'm not exactly sure what you mean by a hard pedal but I'm guessing that your master cylinder piston is not fully retracting and uncovering the compensator port and allowing the pressure to release back into the reservoir.
I think first you need to confirm you have a properly working master cylinder before you replace more parts or try to rebleed the whole system again. The best way to do this is to isolate the master cylinder by plugging it off and bleeding the master cylinder. When you can confirm you have a properly bled and working master then add one half of the rest of the system and make sure that half is bled and working properly before adding the last half of the system. Use you plugs to isolate components when you encounter a problem. Trouble shooting one step at a time will get this riddle solved for you.
This is from Google AI. It might help you understand how your master cylinder works.
A brake master cylinder compensator port is a small opening in the cylinder that allows excess brake fluid to flow back into the reservoir when the brake pedal is released, preventing pressure buildup. This port also allows more fluid to enter the system as brake pads wear down, ensuring proper braking performance. Essentially, it maintains consistent pressure and fluid levels within the brake system. [1, 2]
Here's a more detailed breakdown:
Function:
[1] https://www.helperformance.com/brake-doctor-master-cylinders
[2] https://brainly.com/question/33834361
[3] https://precision-motors-auto.com/the-anatomy-of-your-brake-system/
[4] http://ijariie.com/AdminUploadPdf/D...ted_Hydraulic_Master_Cylinder_ijariie8563.pdf
[5] http://dictionary.dauntless-soft.com/definitions/groundschoolfaa/Compensator+Port
[6] https://quizlet.com/132956744/airframe-op-landing-gear-flash-cards/
[7] https://patents.google.com/patent/US5327723A/en
[8] https://www.obpltd.com/what-is-master-cylinder/
[9] https://patents.google.com/patent/US6672685B2/en
[10] https://www.evoindia.com/features/what-role-does-a-master-cylinder-have-in-braking
[11] http://ijariie.com/AdminUploadPdf/D...ted_Hydraulic_Master_Cylinder_ijariie8563.pdf
Not all images can be exported from Search.
I think first you need to confirm you have a properly working master cylinder before you replace more parts or try to rebleed the whole system again. The best way to do this is to isolate the master cylinder by plugging it off and bleeding the master cylinder. When you can confirm you have a properly bled and working master then add one half of the rest of the system and make sure that half is bled and working properly before adding the last half of the system. Use you plugs to isolate components when you encounter a problem. Trouble shooting one step at a time will get this riddle solved for you.
This is from Google AI. It might help you understand how your master cylinder works.
A brake master cylinder compensator port is a small opening in the cylinder that allows excess brake fluid to flow back into the reservoir when the brake pedal is released, preventing pressure buildup. This port also allows more fluid to enter the system as brake pads wear down, ensuring proper braking performance. Essentially, it maintains consistent pressure and fluid levels within the brake system. [1, 2]
Here's a more detailed breakdown:
Function:
- Releasing Pressure: When the brake pedal is depressed, the piston in the master cylinder moves forward, covering the compensating port. This creates hydraulic pressure that activates the brakes. When the pedal is released, the piston retracts, and the compensating port is uncovered, allowing excess fluid to flow back into the reservoir, preventing pressure buildup. [1, 2, 3, 4, 5]
- Maintaining Fluid Levels: As brake pads wear down, the pistons in the calipers move further out to engage the worn pads. This increased movement requires more brake fluid to be in the system. The compensating port allows this additional fluid to enter the system from the reservoir, maintaining proper braking force. [2]
- Preventing Fluid Buildup: The compensator port also prevents excessive fluid from being trapped in the brake lines. If fluid were to build up, it could cause the brakes to drag or not release properly, compromising braking performance. [2, 6]
- Brake Pedal Depressed: The brake pedal pushes a piston in the master cylinder forward. [3]
- Compensating Port Covered: As the piston moves, it covers the compensating port, sealing off the reservoir. [1, 7]
- Hydraulic Pressure Created: This sealed chamber creates hydraulic pressure, which is transmitted to the brake calipers or wheel cylinders. [3, 8, 9, 10]
- Pressure Released: When the brake pedal is released, the piston retracts. [1, 11]
- Compensating Port Uncovered: The compensating port is uncovered, allowing excess fluid to flow back into the reservoir. [1, 2]
- Fluid Level Maintained: This flow of fluid also allows for make-up fluid to enter the system from the reservoir, compensating for brake pad wear. [2]
[1] https://www.helperformance.com/brake-doctor-master-cylinders
[2] https://brainly.com/question/33834361
[3] https://precision-motors-auto.com/the-anatomy-of-your-brake-system/
[4] http://ijariie.com/AdminUploadPdf/D...ted_Hydraulic_Master_Cylinder_ijariie8563.pdf
[5] http://dictionary.dauntless-soft.com/definitions/groundschoolfaa/Compensator+Port
[6] https://quizlet.com/132956744/airframe-op-landing-gear-flash-cards/
[7] https://patents.google.com/patent/US5327723A/en
[8] https://www.obpltd.com/what-is-master-cylinder/
[9] https://patents.google.com/patent/US6672685B2/en
[10] https://www.evoindia.com/features/what-role-does-a-master-cylinder-have-in-braking
[11] http://ijariie.com/AdminUploadPdf/D...ted_Hydraulic_Master_Cylinder_ijariie8563.pdf
Not all images can be exported from Search.
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mopar head
DoD nuisance Alien/Squatch extermination team
If this doesn`t go right, go to 8min. in.
I mean I’m not the smartest guy in the room that’s for sure but the rod goes in all the way and comes out all the way when I get to pump it. But after 3 pumps when I say the pedal gets hard, it gets hard while having the pedal and rod all the way out, making it nearly impossible to depress the pedal without using a ton of force. Then it kind of slowly depresses and will have a couple little parts when it jumps down quickly. I’ll video it in a bit if it happens.
I’ve bled the MC multiple times, on the car off the car and with 2 different MCs.
I always follow these processes so….
I’m really thinking this is the problem, not using the GM prop valve. From reading it does distribute the pressure to fronts and rears. Which in theory could explain that after pumping a couple of times I have fronts that lock up and rears that don’t. Because more fluid should be going to the front than the rear with the GM style setup.
Check out this page from Summit Racing Summit Racing SUM-760183 Summit Racing™ Brake Proportioning Valves | Summit Racing
GM Disc/Disc Proportioning Valve for 1/2-20, 9/16-18 Outlets
Check out this page from Summit Racing Summit Racing SUM-760183 Summit Racing™ Brake Proportioning Valves | Summit Racing
GM Disc/Disc Proportioning Valve for 1/2-20, 9/16-18 Outlets
Sounds like you're compensator port is plugged or blocked. If the port is open there is no way for pressure to remain in the circuit as the compensator hole provides a direct path to the atmosphere via the reservoir and vent in the cap. Try to loosen each line and observe which line has pressure on it or if both do. Where there is pressure there is a blocked compensator port. if for some reason the piston is not returning all the way it won't take much to block the port.
I just had a wilwood cylinder with a deformed cup seal (probably caused during assembly) that when it rotated to just the right position hung over the compensator port blocking it. The compensator ports are placed very close to the end of the cup and are very small to minimize the lost travel at the pedal that you feel until the cup passes over the compensator port and begins to build pressure.
A working compensator port can sometimes be observed by looking in the reservoir while the pedal is depressed. Wear safety glasses so if fluid squirts out of the reservoir it doesn't get in your eye. Shine a flashlight in the reservoir and look for the compensator port. Have someone depress the pedal slowly you should see fluid movement out the port as the piston moves toward the port. When the piston arrives at the port covering it up the fluid movement will stop and the pedal will get hard in a properly working system. Another thing that will happen is when you are bleeding brakes and you have air in the system. "Pumping the pedal up" will compress the air in the system and if you release the pedal wth air compressed in the system as the pedal is returned and the piston uncovers the compensator port the pressurized air will push a geyser of fluid out the top of the reservoir. if for some reason the piston is not returning all the way it doesn't take much to block the port.
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If you want to test that theory cap the lines going into the porportioning valve and see if your problem persists. I would encourage you to verify you have a properly working master cylinder first.
It shouldn't matter at all which prop valve you have, if any. At least not for the issue you're describing. The mopar prop valve does the same thing.
It sounds like something is keeping fluid from returning somewhere in the system.
Frank Mopar
Well-Known Member
I remember back in the day if the brake warning light went on for low fluid you had to bleed the opposite side of the distribution block to reset it because it shut off the bad side. Yes no?
Inertia
Well-Known Member
Mopars self center when pedal is released, few exceptions on big trucks/motorhomes.
When I cap the front port of the MC (line that takes fluid goes to rear brakes) fluid comes out of the MC with ease.
While the front port is capped and fluid is allowed to flow out of the bleeder screws at each caliper (passenger and driver) fluid flows out of the bleeders with ease.
When I cap the Rear Port (line that directs fluid to front brakes) fluid comes out of the MC with ease.
While rear port is capped and fluid is allowed to flow out of the distribution block to the rear brakes, fluid flows out of the distribution block with ease.
I haven’t tried it at each wheel yet but… I think this means my MC is working properly. Although it definitely needs bled again after shooting fluid straight out of it and bringing fluid right back in.
did it anyways.
Capped rear port on MC (sends fluid to front brakes) and pressed pedal with main line detached from each rear caliper; first passenger side then second drivers side. Fluid comes out of the line with ease.
So… culprit is one of the rear calipers I would assume?
First picture is the passenger side hard line broken from the soft line and the second picture is the drivers side hard line disconnected from the soft line.
Capped rear port on MC (sends fluid to front brakes) and pressed pedal with main line detached from each rear caliper; first passenger side then second drivers side. Fluid comes out of the line with ease.
So… culprit is one of the rear calipers I would assume?
First picture is the passenger side hard line broken from the soft line and the second picture is the drivers side hard line disconnected from the soft line.
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