57 truck brake issue

[lowrodderchev]

Yes sir I do. This issue wasn't happening alot. It was just here and there but the other day was the worst. I'm chalking it up to 115 degree weather and a unnecessary residual valve

[lowrodderchev]

What do you guys think would work better for a heat shield, steel or aluminum diamond plate? I have both and there both heavy gauge

[1project2many]

You don't want a heavy plate. You're moving heat from a trouble spot and radiating it away to a place where there is more room. A thin shield works better for this. Aluminum is a good choice if you have the right hardware to mount it. But mild steel or stainless is fine for most applications. Just make sure the shield is large enough.

[lowrodderchev]

so skip the aluminum diamond plate due to its heavy gauge right?

[dwcsr]

All you need a some 20 gage galvanized sheet and cut out a shield, shape it and attached it some how. If you go thick metal it will hold as much as it reflects.

[lowrodderchev]

guy I work with hook me up with a thin sheet of aluminum diamond plate. worked out great. I ran the truck parked for about 5 minutes the exhaust was pretty hot the shield was cool to a touch. I got titanium wrap coming Thursday for the exhaust and I should be golden thanx guys for the help. I pulled out the front residual valve but I left the back one. I need to make a trip to the auto parts store for a new line.

[lowrodderchev]

all the valves are out, heat shield is in and the exhaust in that area is wrapped with heat wrap. so what I notice is without the residual valve you need to pump it a bit if you need to make a quick stop. other than that everything seems fine. I'm going to bleed them one last time when I get home tonight. I'm starting to think I should just move the pedal to the firewall.

[1project2many]

Sounds like it's done. You might be able to change the master cylinder to one with a slightly larger bore and get rid of the "one pump" issue.

[lowrodderchev]

the master cylinder was a kit I bought for running it under the floor. not sure what bore size or what its off of. it came from MBM brakes I know

[1project2many]

Hard to say without contacting them or getting the original part no (not MBM's #).

[dsraven]

do you have drums in back and discs up front? is the master cylinder made for the combination you have? you can sometimes set up the rear brakes and it will alleviate the pump issue. if they are out of adjustment it takes a bunch of fluid to push the wheel cylinder out till the shoes actually start to touch the drums. set up the park brake first, then the service brake. if you go with a larger bore master then the required effort to push the pedal becomes more.

[lowrodderchev]

Holy crud after running this setup 6 years I just realized its not the right master cylinder. Its a drum/drum cylinder same size fluid wells

[lowrodderchev]

Any suggestions for which master? My current setup is suppose to be a corvette setup.just not sure what year of vette it is

[lowrodderchev]

The wells are 2 different sizes but its,weird the one that goes to the disc is bigger its the well farthest from the pedal

[1project2many]

Corvette masters had the same size front/rear for many years because they are disc/disc. It's ok as long as you have enough fluid storage.

Got a link to the kit?

[lowrodderchev]

[lowrodderchev]

The end closes to the socket has a extended reservoir or as I called it earlier well

[lowrodderchev]

No I dont I got it years and years ago from American classic truck parts its the mbm kit

[lowrodderchev]

One other thing I notice is she I pulled the lines to master that go to the brakes there wasn't any pressure. After I pulled the line a little drizzled out but it didn't go gushing out

[1project2many]

There shouldn't be a gush of fluid. Usually it will drain out fairly quickly though.

That does look the Corvette master used from '67 - '81. Parts books seem to show all the M/C used with power brakes were 1 1/8" while manual M/C are 1". How does your pedal feel? Stop ok without too much effort? I see a 10 bolt axle in the rear... any idea what it's from?

BTW, looked at the build thread. What a great looking truck!

[lowrodderchev]

Its off a 80 Camaro also notice my proportion valve was tripped i pulled it apart and cleaned it up and sprayed they heck out of the master cylinder to with brake cleaner. Going to do a bench bleed and reinstall it. Do I need to bench bleed the proportion valve to?

[lowrodderchev]

I'm getting a new master. Tried to pump it the back reservoir isn't responding. Looks like the plunger is jammed up inside

[1project2many]

Prop valve should bleed. If it's a GM style combination valve you may need to lock the pin in place.

[dwcsr]

Originally Posted by lowrodderchev

I'm getting a new master. Tried to pump it the back reservoir isn't responding. Looks like the plunger is jammed up inside

Some of these are step bore masters so you don't depress them all the way while bench bleeding. Push in a half inch at a time other wise you damage the rear cup. get hold of the tool to keep the prop valve centered while you bleed. most after market valves use a screw in tool that goes in where the warning light switch is.

http://www.ebay.com/itm/Combination-...-/111607889429

[lowrodderchev]

As I was bench bleeding it I notice I wasn't getting any action in the back reservoir I purchase a new one im in business had to adjust the pedal rod but its stopping and no brakes are dragging the proportion valve was pretty nasty inside so I pulled it apart and cleaned it check it its still centered thanx guys fir the help