I have a '90 F150 and both the yellow ABS light and the red BRAKE light are on.

It was fine until my buddy did a little brake work for me, including replacing a couple brake lines and a parking brake cable. He bled the system at the lines going into the front calipers because the bleeder valves on the calipers where corroded and frozen. I then replaced the calipers and bled the system properly. Three times. I don't think the problem is from the brake work.

The brakes still work, by the way. The pedal just feels a bit spongy and I think the brakes don't work as well as they could.

If the truck is not running, I can pump the brakes a few times, and it will make a sound like it's sucking air a few times. Then the sound stops and the pedal firms up.

If the truck IS running, it keeps making the sucking air sound no matter how many times I pump it, and the pedal feel stays the same.

I think it might be a bad brake booster. Just wanted to see if any one else has a different opinion before I go out and spend my money.

 

it sounds like you have a problem with some part of your rear antilock system.

 

Could be a problem back there, given the ABS light being on. Maybe my buddy damaged something messing around back there. Where is the ABS module?

Still, it doesn't explain why I get the sucking noise by the pedal where it goes into the booster.

 

Anybody else have any ideas? Maybe I should have posted this in the general 87-96 forum.

 

the abs module should be under your left foot on the drivers side on the frame it is bolted on the frame and has brake lines coming out of it ill look to see if I can get a pic. good luck

 

if you get a sucking noise it would be the booster the front of the booster comes thru the front of the cab and it sounds like you have a bad seal and when you don't have the petal pushed in it holds the vacuum in and doesn't make a noise what I would do is press in the petal and see if you can feel any thing around the front of the booster in side of the cab if you feel it sucking in it is bad. also check and make Shure that you have the right calipers on the right side.

 

also check the rabs Module it is located under the dash on the passenger side against the firewall. that could also be the problem

 

Thanks for the suggestions, guys. I will look into those areas. As soon as it stops raining lol.

 

let me know what you find out

 

Well, I felt around the area on the firewall by the brake booster while I pushed on the pedal, but I couldn't feel any air moving around. It just makes the sucking sound. But I also went and started up my Mazda car, and it makes the same kind of sound, just not as loud, probably because it's a compact car. The vacuum hose from the manifold to the brake booster under the hood also looks good. The pedal doesn't exactly feel all that responsive, but then again, it is a truck. It's probably the same as every, and I just never paid that much attention. The brakes definitely work fine. So I guess I'm going to have to start replacing ABS sensors and see if that does the trick.

 

Ok cool it's almost 10pm here so Tomrrow I'm the afternoon ill start my 83 up and see what sound it makes it has the same brake system

 

Well, I went out during a break in the rain today and bled the ABS hydraulic control valve. No difference.

 

Well both of the lights could be unrelated I would say to check the parking brake it could be stuck and you not know it if it's stuck even a tiny bit it will turn the light on

 

If you have the truck in drive with the brakes on does the pedal fade away and go twards the floor of stay the same ?

 

Well they could be unrelated. My friend put on a new e-brake cable and didn't bother to adjust it. I've just been putting it in gear to keep it from rolling, which brings me to the next point. The truck is a manual, so I can't put it in park, seeing as how manuals don't have park. How inconvenient.