In need of info on rear disc convertion

[4wheelattitude]

I thinking about doing the rear disc convertion on my 1970 GMC shortbed. I'm not sure about the prop valve issue? Could I just go to the local salvage yard a get everything I need for this with exception to the mounting plates?

 

[shane74]

Some trucks need a prop valve, some don't. I don't recommend installing them until AFTER you have done the swap. AFA using junk yard parts, I wouldn't. Brakes aren't something you want to mess with.

 

[4wheelattitude]

Would it be worth the effort to do the rear brake covertion?

 

[sweetk30]

my one ton with 6500 lbs of weight and 38 tires stoped good with disk / big 13" drum. then swaped to disk in rear. wont ever ever go back stop on a dime. and no more major panic stops also from dumb drivers.


i like disk rear so much that shane74 is helping me with a project to convert a nother custom setup.

 

[sandawgk5]

i like dick rear so much

Ira

 

[sweetk30]

Ira

stop it sailer thats not funny

 

[ntaj*ep]

On the system you have if you go with a master/power booster from a K20-30 or I think the Subs also had the same units. You will be set, prop valve shouldn't be an issue.

 

[Beast388]

A 1970 GMC would have drums at all corners so I guess if it were me I'd get a prop valve from a vehicle that was at least disc/drums.

I assume you have already swapped the front to discs?

For what its worth, I am using the stock MC, booster and prop valve on my 71 GMC with 4-wheel discs and my Burb stops quite well.

 

[cybrfire]

Would it be worth the effort to do the rear brake covertion?

In my opinion its one of the best upgrades out there when done correctly. Like said above some need to mess with the prop. valve and some don't. So far I have been lucky. I've installed about 7 of these now and never needed to do anything more than have them power bled. Get that done and the pedal feels like a rock!

 

[4wheelattitude]

Yup! I did switch the front disc some time ago. However I never did put a power brake booster on the truck. It takes some fancy foot work to slow her down sometimes. I've got it in the garage putting the 700r4 in now. While it's there it's going to get power 4 wheel POWER disk brakes, new rears, rebuilt transfer case, factory a/c, 33" tires, 4" lift, factory tinted windows, new bumpers, and really sweet pain job. Just keep it quiet the wife dosen't know yet! Thanks for all the help.

 

[86chevybanshee]

rear disks are well worth it, i just recently put them on my truck, i used the stock prop. valve, i need a new master tho, mines not getting full rear stopping power.

 

[RootBreaker]

when I had drums... I was going down the road and someone cut me off.. .I hit the brakes and the ass end flew out from under me to about a 25 degree angle.... should have seen their faces when they heard 40x17 hawgs barking on the road.....
scared me though.... so I had the parts for the rear disc swap but just didnt do it... waited until after inspection...

then I did the rear disc swap... I can hit the brakes hard now and she dont do that now.. more controleable... I may have had the rear drums adjusted too much or something but I love the rear disc... also easier to change the brakes now.. plus funny when people look at it and say .. .that is a 70's truck right????

I say yes.. and they