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Old 08-16-2018, 08:19 PM
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David Henry David Henry is offline
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Default Brake Issues

Recently Paul and Ed had a discussion on maintenance and specifically brakes. We replaced the front brakes, rotors, calipers and pads and replaced the rear wheel cylinders and hard brake lines, and flushed the lines with all new fluid, bled the lines and took the car for a ride. When depressing the break pedal, the car wants to abruptly pull to the right.

Otherwise the steering and tracking is tight, just pulls when depressing the pedal which is firm. Before changing the brakes, it did the same thing, except pulled to the left.

Current owned:
1974 Sayers and Scovill Professional Ambulance
Previously owned:
1973 Miller Meteor Lifeliner Ambulance
Future ownership:
1971-1973 Wayne Sentinel Suburban Ambulance
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Old 08-16-2018, 08:38 PM
Rich Koski Rich Koski is offline
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Default We just worked on ours too

We found that the rubber lines running to the calipers in front had deteriorated and were obstructed which caused fluid to pass through unevenly. The car used to pull one way on braking and after changing one line it pulled opposite. We will be changing the second line soon which we believe will balance out the braking. We have also heard that a faulty proportioning valve could cause this.
1960 Superior Three Way Hearse
1969 Superior 51" Royale Rescuer Ambulance
1972 Miller-Meteor Combination Ambulance/Hearse
Previously owned: 1968 MM Hearse & 1971 MM combo
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Old 08-16-2018, 09:52 PM
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all three of the rubber hoses will effect it a lot. people tend to forget the rear one but I have seen them lock the rear brakes and not release. but this last set I put on the 67 were the metallic linings bad choice to get. there all drum brakes and the metallic work best when hot. the first stop is a maybe. but me I would re-blead that wheel not grabbing as after driving it some you may have a little air in that one. but the proportioning valve onle tries to balance the front and rear not left and right
drop in for coffee anytime
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Old 08-16-2018, 10:44 PM
Paul Steinberg Paul Steinberg is offline
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I will agree, that when doing a brake job, it isn't complete, unless you replace both front rubber hoses, and the one over the top of the differential. As for the proportioning valve going bad, I don't doubt that it can happen, but I haven't seen it happen once in over 50 years of dealing with disk brakes. My first experience with disk brakes was a 1967 Pontiac with 4 piston calipers. Most people never properly bleed the calipers, and that is with a pressure bleeder. If you don't have a pressure bleeder, then the second best method that I use, is to fill the master cylinder, and leave the cap off. Then open the farthest bleeder (right rear), attach a rubber hose to it, and place the end of the hose into a container that has some brake fluid in it. Mark the container with the level of the fluid, and wait 15 -30 minutes and when you see that the container level has risen some, remove the hose, and tighten the bleeder. Then go to the second farthest (left rear) bleeder, and repeat the process. Then the third (right front), and lastly, the forth (left front). After each wheel, check the master cylinder level, and refill. Never let the fluid level in the master cylinder go to the bottom. If you do, then you have to start all over again.
If the wheel cylinders are new, and the same for the front calipers, it will take longer to fill the chamber, and to get the air out of the system.
Last thought... check the tire pressures, and make sure that your alignment is correct. Mismatched tires can also cause a lot of issues.
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