kenttrudiw

Hello, my 16 year old Daughter bought a 1999 Cherokee as a first car! Been cleaning in up, changing some fluids etc...

The issue she has short (girl) legs, she has a hard time compressing the brake peddle at stoplights. She has to push real hard to keep Jeep from creeping forward...

I checked the front brake pads they are fine, I flushed all brake fluid and filled with new, that seemed to help, but still not quite enough....

Is their anything else I could do? Thanks.....

rivercrazy

Check the vacuum booster. There should be a hose coming off the intake manifold going into the brake vacuum booster (big round thing behind brake master cylinder). With engine running in park, pull hose from booster side and make sure it has vacuum.

kenttrudiw

Great, thanks... I googled that and found everything I need to know about a brake booster...... I hope it is just a small leak in the vacuum line...

Rmart30

also check the rear brakes and make sure they are adjusted properly. If they arent they can give a low pedal.

nasonguy

+1 on the brake booster, it's probably just that the line has a leak.

Get yourself a vaccum guage...

Just FYI though, when you pull that VAC line off with the engine running, the idle is going to shoot up to about 2 or 3 thousand RPM, it's not gunna hurt nothing, but it will surprise you if you've never had a vac line come off before. Also, it'll probably stall the motor when you plug it back in... Again, won't hurt a thing, it'll just surprise you...

rivercrazy

Man, don't ruin the surprise! lol j/k

nasonguy

Oops!

Lol.

TrekkerJmm

You may also want to check the rear wheel cylinders. One side may not be working as was the case with mine...Tj

kenttrudiw

Thanks guys for the great info... I hear a very slight vacuum kind of a sound, but it is new to us, so not sure if it is normal or not in this Jeep... Maybe it is this very line which is making the noise, and causing this brake issue.....

XJ?2010

The problem may be internal to the brake booster. Theres a rubber diaphram in there that uses atmospheric and engine manifold vacumme to assist the mater cyclinder.


Check the brake booster

http://www.type2.com/library/brakes/vacboo.htm

Carl48

Run the engine at idle for at least a minute then shut it down. After a minute or two pump the brake pedal...there should be vacuum assist for the first stroke or two then the pedal should only travel slightly and feel firm. Holding light pressure on the pedal, start the engine, the pedal should fall towards the floor a bit then firm up. If all this checks out, your brake booster is OK.

kenttrudiw

Great info, I did this test vacuum booster checks out just fine... I need to get a vacuum tester to check my total vacuum.... When I pulled this tube, the engine only went to around 1200 rpm or so, plugged it back in and the engine did draw way down, but not too much....

But maybe I just don't have the needed vacuum coming off the engine... But of course I don't have a problem with the brakes, of course my Expedition is five times easier than this Jeep to stop...