I have a question

[CameronT]

I have a brake booster in my 77 620 that is bad, wondering if a early model 720 booster will work?

[jastrunk97]

Some research goes a long ways! Some people will give you a TON of crap for it so always research before you ask. Took me ten seconds and found this http://community.ratsun.net/topic/504-720-brake-booster-in-a-620/

[CameronT]

Thank you for the link!! I appreciate it

[datzenmike]

I have a brake booster in my 77 620 that is bad, wondering if a early model 720 booster will work?

.

 

Well first... is it bad???? What makes you think it's bad?

 

 

Try this....

 

Pump brake several times to remove any residual vacuum. Now press down on the brake pedal normally and hold. Start engine. You should feel the pedal drop slightly as the vacuum builds. This is normal operation and shows the booster seems to be working..

[CameronT]

I have to pump it several times to stop,

But I have tried to pump it than turn it on nothing happens, it stays hard and I let off and it goes back down to the floor, the m/c is about 20k new also

[CameronT]

20k old sorry

[CameronT]

I just tried it to double check the pedal moved down a hair

[jastrunk97]

Bleed your brakes before you buy anything

[CameronT]

I'll give it a shot but I have done that a bunch helps for about a mile down the road

[datzenmike]

Not the booster.

 

First raise each wheel and turn the brake adjuster out until you can feel the brake shoes rubbing when you try to turn them. Now pump the brakes several times to center the shoes in the drum and repeat until you can't adjust them out any more and the wheel is just easy enough to turn by hand. Now do the other three.

[CameronT]

So it'sjust my shoes are possibly loose in there? That explains when I would come to a stop, the first one each time I'd drive I'd here t thud my brakes moving?

[datzenmike]

They wear down and the shoes have to travel further and further to rub against the drums taking more and more pedal travel. There's four of them so it adds up to a lot real fast.

 

You may also have some air trapped in the lines but the adjustment has to be made anyway.

[CameronT]

I'll give that a shot and let you know, it'll be a couple days but

[datzenmike]

You may have to loosen the hand brake slightly on the rears, get them set, and then reset the hand brake.

[CameronT]

My e brake is shit too, it's all new but I might just get new brakes anyway all the way around, might as well do it all