I have a 1990 lwb montero I just bought. there was no brake fluid in master cylinder when i bought it. I filled it up and pumped the brakes so i could try to find where the problem/leak was. It seems to be leaking from where the master cylinder meets the brake booster. I've never dealt with master cylinder or booster before, is there just a gasket between the two that could be bad, or is it one or both parts that are bad. Thanks.

Orings in the master cylinder. Go pick up a new one. Be sure to bench bleed it before you install it.

2nd that... especially the bench bleeding part! <img src="/forums/images/graemlins/kewl.gif" alt="" />

Eric W.

never had to replace master cylinder before. does bench bleading mean filling it with brake fluid and bleading before installing back on booster? thanks again

It should come with small plastic hoses. Before it goes in the truck, fill resovoir with fluid, connect the hoses to the MC and put the other ends of the hoses into the resovoir. Pump the end of the MC with a screw driver or whatever fits into the end. Keep pumping until all the air is gone. When you install it into the truck, bleed all the brake lines. If you are not sure you can do all of this, get someone that knows what they are doing. No brakes can be very bad.

A new MC should have instructions.
Be careful with brake fluid, it likes to take paint off of stuff, including your Montero.

thanks for the good info...that sounds relatively easy. i had just bought this vehicle and am having a real fun time(ha) with the fuel pump assembly. luckily the mc seems easy to replace and pretty cheap for a reman one.

Actually you can buy a rebuild kit (no hoses come with it) for the master cylinder. You can also buy a new reservoir and cap from the dealers. <img src="/forums/images/graemlins/kewl.gif" alt="" />