H3 Brake Master cylinder

1, Is there a rebuild kit available? Where? price?
2. Can one be rebuilt or repaired?

Very Urgent - I need the H3 for work selling real estate.

Where to buy? Best price?

What is the problem with mine? I have to piush extremely hard on the pedal to get about 10% braking power. Is there an upper and lower half of the pump most likely to be the problem? Can I replace just the bottom half.

 

The problem : I need to push extremely hard to get 10% braking power. What do you think is the problem?
Can it be fixed by replacing either of the above or as pictured?

Mucho Gracias.

 

You need to diagnose your problem BEFORE buying parts.

There are many possibilities for your issue.
Insufficient vacuum, vacuum leak in the hose to the booster.
Bad Brake Booster.
Bad Booster Check Valve.
Poor electrical connection to the Booster.
Bad Master Cylinder.

Those are the common things to look for and it could be one, or a combination of more than one. There is stuff all over the internet on how to diagnose what/which is your problem. Do the simple stuff, check the vacuum hose and electrical connections to the booster for compromise, fraying, cracks, corrosion etc... Then move to more diagnostics.

Being in a hurry usually cost $$, get a rental if you have to. Fix it correctly once instead of throwing parts around.

I think with the H3 when you buy the GM Booster it comes as an assembly with Reservoir, Master Cylinder and Booster.

 

100%, please don't throw parts at it without diagnosing the cause.

 

Its with the meachanic - in the Dominican. In our little town we have like 5 white hummers circa 2006. Meachanic ( German) suggests maybe the moter built into the pumkp