No power brakes

[NiNeTy Fo SHO]

I just replace my intake with a painted one I had. I also replaced the valve covers (sealed them up as I was getting oil in lug wells) and did the throttle body/iab coolant bypass mod. Now, no brakes.

When I press the brake pedal, it doesnt go down at all. On the very short drive I took it on, I could stand on the brakes and the car would slow down...but it took awhile for it to slow down.

No CE light (havnt checked for codes). Reservoir is almost full. Car has been sitting for about 2 weeks. Brakes worked fine before anything else was done.

Did I disconnect something? I looked over the reservoir and what I think is the distribution block below the ********* box in front of the intake box (with filter).

Dont know much about the brake system. Teach me oh wise ones.

I did notice that it clicked after I pressed on the brake pedal and would let off. Dont know if that is related or not.

 

[CerberuS]

Look at the brake booster (big round black thing behind the master cylinder) You should have a big vacuum hose connected to it.

This goes into the intake near the TB i think. And it gives you your braking power.

 

[NiNeTy Fo SHO]

I have looked at the hose...and it looked like there was a slight kink in it so I reached down to straighten it out (while it was running)...but didnt seem like it was doing anything. I will go double check it.

EDIT: Just checked it. Made sure there was no kink. It turn pretty quick coming out of the ********* round thing. That hose (black with red stripe) runs up to the firewall. Another smaller black hose goes from the intake (near the IAB) down pass that and up towards the radiator. This hose also has a junction with a sensor of some sort that has a wire clipped to it.

 

[NiNeTy Fo SHO]

Bump for the day crew...

 

[rangerj]

If the brake pedal is super hard, that is you have to stand on it to get stopped, then the power brake booster is not gettig vacuum or is bound up inside or mechanically. Given the work you just did I would bet a brake booster vacuum hose or connection is at fault.

 

[NiNeTy Fo SHO]

Care to elaborate any more on this rangerj?

I have checked the fuses...all look good. I checked the line coming from near the IAB going down towards the brake booster...when I remove it, the intake starts sucking air in through the ******. When I was under changing the oil, I checked the few lines hooked up to the brake booster...I think 2 of them...both seemed fine.

Maybe I just dunno where to look...

 

[rangerj]

Additional thoughts (elaboration);

Is the pedal "up" and hard as a rock, or is it on the floor and cannot be pushed any further (standing on the pedal)? If the brake booster is functioning properly then the pedal may feel hard because the master cylinder has failed internally, e.g. the pistons have bottomed when the pedal is pushed and cannot be pushed any farther. This is one of the mechanical failures I was referring to. The brake fluid by-passes the cups on the pistons (an internal leak in the master cylinder). The other possibility is some sort of interferance with the movement of the brake pedal lever or booster actuating rod.

Have you looked at the vacuum connection on the booster. Sometimes the hoses are OK, but the connector is broken below the exterior surface of the booster. I have only seen this a couple of times, but it does happen. There are tests than can be done to determine if the booster is functioning properly and I'll post them if you think that might be helpfull.

 

[NiNeTy Fo SHO]

The brake pedal is up and does not want to move down at all.

The brake booster is the ********* round thing near the radiator drain valve, correct? (Just making sure I am looking at the right part.)

An aside...I checked the front brake lines at the caliper and they look to be ok. Also, ABS light comes on at start of car and goes off as usual.

 

[NiNeTy Fo SHO]

I have slightly tugged on the vac lines (2 I believe) to see if they were connected and they seem fine.

 

[rangerj]

The power brake booster is mounted on the firewall in front of the driver and the master cylinder is mounted on the brake booster. I think you are referring to the cruise control unit.

 

[NiNeTy Fo SHO]

Yes I am...I checked it and the wire coming out goes to the throttle body to hold it open.

So I was in the wrong area. I noticed the brake boosted on the firewall under the reservoir...now to investigate more on whats wrong.

 

[NiNeTy Fo SHO]

2 hoses run from the brake booster area over to the passenger side into a black plastic "housing". Out of this housing goes a larger hose to the rear of the intake. What does this do? I am thinking the port off of the rear of the intake may be clogged (put a different painted intake on and attached hose to new intake).

 

[NiNeTy Fo SHO]

Thanks for the help rangerj and Cerberus.

The large hose that connects to the back of the intake near the passenger side ending up being the problem. It was connected, but the right angled coupler screwed into the intake was full of crap in the ID of the threaded part...so I never seen it when looking in to connect the hose.

Cleaned it all out with a screwdriver and some carb cleaner, now the brakes are right back where they were.

Im just a retard looking at the wrong parts.

 

[CerberuS]

Glad you fixed it