89Suburban Brake Master Cylinder Leak Repair and/or Install

[89Suburban]

Auto Zone says they need to know if I have a JB5 or JB7 brake system????

Anybody here can tell me how to figure that out?

I want to buy one on Sunday and install it.

I got some leakage on the current one, I do not think it is the cylinder going bad, I think it is leaking from the 2 tank seal rubbers. Anybody fix just the rubbers before?

 

[HotRodPC]

I'm gonna guess it to be JB5, and the JB7 is 3/4 ton. So unless you've got an upgraded brake system for a 1/2 ton, it should be the JB5. Best way is to make sure they have both in stock, then take yours off and match it up.

 

[89Suburban]

No can do, I need to drive the burb to get the part, then head over to work to put it on.

 

[davbell22602]

No can do, I need to drive the burb to get the part, then head over to work to put it on.

What if you take the part off at work then ride a bicycle to get the part? How far are you from the parts store to work in a bicycle ride? Or even walking distance?

 

[RetroC10Sport]

Is the SPID label still in the glovebox? Or wherever it was put in a 1989 Sub.

JB5 = 6400 lbs GVW
JB7 = 8400 lbs GVW

 

[89Suburban]

What if you take the part off at work then ride a bicycle to get the part? How far are you from the parts store to work in a bicycle ride? Or even walking distance?

A bike, yeah, that is my first idea in a winter storm conditon, LMAO!!!!!

 

[89Suburban]

Is the SPID label still in the glovebox? Or wherever it was put in a 1989 Sub.

JB5 = 6400 lbs GVW
JB7 = 8400 lbs GVW

I have my RPO code label posted in here somewhere, will that do? Or can I lookmin the door jamb fornthe weight class. I am on my ipod right now, I'll look for that pic later tonight or tomorrow.

 

[RetroC10Sport]

Yeah, the RPO label will be best.

JB5 buddy.

 

[Old77]

 

[89Suburban]

Yeah, the RPO label will be best.

JB5 buddy.

 

[89Suburban]

Here is some pics, any thoughts? Think it is just the lid leaking?

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[crazy4offroad]

Unbolt it from the booster, if there's fluid in the back then the rear seal is leaking. Otherwise I would just say it's the lid.

 

[89Suburban]

Unbolt it from the booster, if there's fluid in the back then the rear seal is leaking. Otherwise I would just say it's the lid.

I'll do that next time I open the hood, thanks for the tip.

 

[HotRodPC]

Get some carb or brake cleaner, clean the booster off and then watch it too. Seems to be alot for the lid to be leaking, but I guess it could be.

 

[davbell22602]

Is the gasket/seal on the brake fluid lid in good shape?