Creaking brake pedal

[vxaxv17]

For the past month or so now my brake pedal has started creeking when i step on it to the point where everyone in the truck can hear it. Its really quite annoying. It seems that the softer and slower i press the pedal, the more it does it. Getting up under the dash i can see/hear that it is coming from the point where the piston pushes into the cylinder. Now to add to this, i have also recently noticed that the area around the master cylinder at the firewall looks somewhat wet like it has been leaking. There also appears to be a slight amount of liquid (could be brake fluid but its pretty dry and sticky to the touch) running down the inside of the firewall under the dash right where the brake pedal is.

 

To me, this points to a leak somewhere but it has to be quite slow as the wet area is small and the fluid level in the resevoir is well above the low fill line. The brakes work fine and i have not noticed any other problems except for what i mentioned above.

 

Do you think the creaking is related to the leaking (haha i rhymed ;) ) and is there anything i can do about this myself?

 

Thanks,

Jim

[GM-Tech]

Do you have hydroboost or a vacuum booster? Hydroboost is the one with power steering pump hoses going to it. Vacuum is a big, black can.

[vxaxv17]

What do you sit and wait for people to ask questions cause you are always right there with a response ;)

 

Anyway, sorry for not mentioning it earlier but i have the hydroboost. There is no large can at all and there are definitely power steering hoses running to the master cylinder. I honestly had no idea such a thing even existed until you asked. Now that i think of it, i didnt even mention in my first post what sort of truck i have. Sorry about that. In case anyone needed any more information, its a 2002 sierra 2500hd 4x4 with the 6.0L engine. It has about 65k miles on it.

 

I posted a picture of the firewall area at:

 

http://www.vxaxv.com/public/truck/brakes/1.jpg

http://www.vxaxv.com/public/truck/brakes/2.jpg

 

You can just about see the leaking i am referring to on the small blue cylinder in the picture which is right above where the steering shaft comes through the firewall. Sorry about the crappy quality, they are from my cell phone.

[GM-Tech]

Actually, due to a medical problem I've only been working part time these days so I have a lot of free time on my hands with nothing better to do. So I check in here frequently.

 

Not bad photos for a cell, but I still can't see much. If you don't see anything liquid or very wet, I wouldn't be overly concerned. Wish I could see it better. If it were me, I'd wash it all down with brake clean and monitor it to see if it comes back or how long it takes and what it's point of origin is.

 

As for the noise... dunno on that one. I have heard vacuum boosters make the kind of noise you described, but not hydroboost. Could it be in the pedal itself?

[vxaxv17]

Thanks again. Im at work right now so i dont have access to my digital cam. I'll take a better picture this afternoon when i get home and then do the cleanup like you suggested. It wasnt so much the crap around the master cylinder that i was worried about but rather the liquid running down the inside of the firewall under the dash. I'll investigate a little more when i get home.

 

Jim

[vxaxv17]

Well i got some better pictures so i figured i'd update this.

 

These are 2 better pictures of the leaking i was talking about at the master cylinder.

 

1:

 

and 2:

 

Also, on the inside of the truck behind the pedal looks like this:

 

You can see the piston at the very top of the picture where it goes through the firewall and the fluid thats leaking down under the dash.

 

Now that im looking at the pictures, it actually looks worse than i thought. Any ideas what might be causing this?

 

Thanks again,

 

Jim

[Koinz]

Hi Jim,

 

First of all, Nice Truck pic in your profile.

 

If you can determine whether the leak is power steering fluid or brake fluid that would help. I'm thinking it's the hydroboost unit.

 

I have never had one of these hydroboost unit's off, so I'm not sure if a brake fluid leak from the master cylinder can leak back through the hydroboost to the firewall, probably not.

 

Good Luck

[vxaxv17]

Hey Koinz thanks. Just from looking at it, it does appear that it is somewhat darker than brake fluid so it could very well be power steering. I'll take a closer look and see what i can find.

 

Thanks again,

 

Jim

[GM-Tech]

Personally it looks like months and months, maybe years of accumulation. Since I don't believe there are parts available on this thing for repairs, you'll have to replace the entire hydroboost assm. and at that cost, I would be hesitant for what ya got there. As I said, clean it off and see how it goes.

 

The stuff on the inside looks like some sort of sealer or maybe assembly lube. If it was thin, like p.s. fluid, it wouldn't leave that kind of trace. The master cylinder definitely can't get fluid by the hydroboost unit to get brake fluid into the vehicle.

[Valsport]

so what about solving the actual creaking from the brake pedal? i dont have those type of leaks but a lot of creaking.

[lagrange151]

How about some lube on the pivot points.

[pm26]

How about some lube on the pivot points.

 

<{POST_SNAPBACK}>

 

 

 

Yes, I second that. I had a very annoying clutch pedal squeak in my Mazda that was driving me crazy. At first I thought that it was the clutch master cylinder piston squeaking. Turned out it was just the pedal pivot point bushing. All it took was a squirt of WD 40 in the right location to solve that problem.

[vxaxv17]

Hate to bring this up yet again, but i have some updated information.

 

I have cleaned the whole hydroboost/master cylinder using a degreaser and a toothbrush. It was quite dirty. I also wiped the area clean under the dash.

 

After a couple days of use, i popped the hood to check if it was still clean. Well, its not. Some sort of fluid is definitely leaking from the area where the hydroboost meets the cylinder. You can see it in the picture below. This is the underside of it by the way:

 

 

There is also no question about the fluid leaking under the dash. After pulling back the carpeting a little, i can see even more of it. It appears to have been leaking for quite some time. In the picture below, you can see where the brake pedal goes through the firewall into the cylinder. There is fluid leaking out of that area and traveling down the wall behind the black plastic/rubber cover and eventually under the carpeting.

 

 

You can also see it pooling down by the gas pedal:

 

Does anyone know what could have happened to cause these leaks? I find it hard to believe that anything leaking under the hood could somehow get under the dash like this so that leads me to believe that there are 2 separate problems. Before i bite the bullet and bring it to the shop is there anything i can replace myself to fix this?

 

Thanks again,

 

Jim