MC leak. Rebuild or replace?

[CRM]

I was looking at my stereo wiring today in preparation for an amp installation when I saw this at the firewall.I'm including a picture of the engine side also. Are all rebuild kits the same or is there one in particular I should be looking for?

 

[74 Shortbed]

You need a kit for a JB1 M/C

 

[RetroC10Sport]

I always replace them with new. Master cylinders can have pitted walls which cause major headaches.

 

[CRM]

I'm actually going to buy the whole MC but I'm seeing bore sizes of 1" and 1 1/8". Maybe I'll pull the existing one and take it with me to the parts store.

 

[Rusty Nail]

Replace.
Ya, take it with you.

Dude. That's nasty lookin! Eeeeeeeeeee!

 

[HotRodPC]

Be sure to get some brake cleaner and spray that firewall off clean. Then spray it with some WD40 or other lubricant. That brake fluid leaking there will eat up and cause your firewall to rust away and give way when you hit the brakes real hard someday. Get a handle on that ASAP and stop that rust problem that is going to happen.

 

[HotRodPC]

Also, if you wanna, nows the time to convert to power brakes too. Just go to the Pull it yourself parts yard and pick up a brake booster and MC. It's not hard at all to do. It's all bolt in. I've lucked out before and found what appeared to be a new booster and master cyl combo. Seems like I paid $24 for both pieces and they worked like brand new too.

 

[CRM]

I just might have to visit the You Pull It yard.

 

[CRM]

Just found a guy on Craigslist that lives about 15 minutes away who has 3 '79 SB's he wants to part out. Going by after work to see what he's got. Maybe there's a power brake package available. Do I only need the power booster and MC or do I need additional parts?

 

[da_raabi]

You may need the pedal assembly too, sometimes the pedal ratios are different between power and non-power.

 

[HotRodPC]

The one I converted, all I need to was the rod that went to the power booster and that was it. A direct bolt in swap, no pedal change needed. I certainly can see how that's possible on some models, but I don't believe it is on Squares.

 

[HotRodPC]

You may need the pedal assembly too, sometimes the pedal ratios are different between power and non-power.

And maybe just a matter of moving a pin in the pedal arm too. Certainly worth checking out and comparing on that 79 he's going to look at to see if the rods come in at the same place.

 

[CRM]

Went out to the farm that had the 3 Sb's. Wow what a pile of junk!

 

[HotRodPC]

You've got front disk brakes right? Just not power front disk brakes.


I just recalled something too. @RetroC10Sport said something about power brakes and the wide brake pedal blah blah blah. He'd be the one to confirm if brake pedal needs swapped to convert from Non Power to Power brakes.

 

[CRM]

Since it's not a daily driver I think I'll just go with standard brakes. My only question now is do I have JB1 or JB3 ? My RPO code sticker doesn't say. I've looked at different tags around the truck but nowhere do I see it. I don't tow anything, or even carry anything heavy, so I think JB1 would be ok.