Firm brake pedal, but very weak brakes

[pizzaman09]

The brakes in my current Comanche are pretty strange.  The pedal is awesomely firm but they feel like there is no assist.  Stoping force is very low.  Does this sound like a bad booster?  It's almost identical feeling to my Austin Healey Sprite with fully manual hydraulic brakes.

The other Comanche I had years ago had a very soft pedal that basically went to the floor, but it had lots of assist.

 

My current Comanche is a 1990 Eliminator.

[cruiser54]

Sounds like you're on the right track. 

[Pete M]

my 88 had a firm pedal that became worthless as soon as the engine was started.  replacing the booster fixed it.  

[cruiser54]

think "upgrade" if you need a booster. 

[Pete M]

excellent point.    be sure to look into the dual booster swap from an later XJ or WJ.  should be links to it in the link in my signature.

 

[pizzaman09]

Cool!  Thanks for the advice.  I've seen the discussions on upgraded boosters, I'll check them out.  

[Parei_doll_ia]

Check that vacuum on the booster too. Mine was like that when I first bought it, but it had a leak. I later put a wj booster and master in

[pizzaman09]

I should check the vacuum in the truck.  I've suspected it is low as the vacuum disconnect axles are very unreliable.  I'm still working through the cruiser54 tips, I know I have bad sensor grounds in the engine resulting in an idle about 300 rpm, which won't help vacuum.