Today I changed out my front brakes with the Centric 2 piece kit and Wagner Thermoquiet semi-metallic pads (I also replaced my coil over front shocks, but that would be another thread). It was my first time to do a brake job and the prelim neighborhood drive around went well. I broke them in with 5 moderate braking stops and then 5 "get on them a little hard" brake stops. I had both windows down and could not hear any noise. The rotors were pretty hot when I pulled in the driveway though. I guess that was to be expected.

Now I need to do the rear brakes. Does anyone know the Centric part number for the rear rotors? As the thread title says, there is a wet area on one of the rear hubs I discovered when changing rear shocks last week. I guess I have a caliper that is leaking. I read in my Chiltons to never change out a caliper on just one side. Mr Chilton says do them both.

One thing that was really weird about the brake job. I decided to do the turkey baster thing and get all the old green brake fluid out of the reservoir and refill it with fresh Dot 3 synthetic fluid. After filling the reservoir, I got my Mighty Vac out and hooked it up starting with the front driver side. Even though the guage showed I was holding a steady vacuum, when I opened the bleeder screw I got more air than fluid. It was as if the seat on the bleeder screw was letting a ton of air in the vacuum. I bet I had to pump the Mighty Vac up 20 times just to fill the little container up one time. I just let it pull air and fluid until the vacuum got down to 5 on the guage and then blocked it in. I repeated this as I said about 20 times. When I went to bleed the passenger front side it was the same thing. I did get the fluid evacuated until it was pretty much clear so I guess it was a success. When I started the truck and pumped the brakes, they went to the floor about twice and then firmed up to where they felt great. That was my first time using the Mighty Vac and I didn't really care for how it went. Just seemed weird all those million air bubbles. I never came close to getting a solid stream of fluid.

Truck has 162k on it.

 

I prefer to start the process by pumping the brakes with the bleeder screw cracked. This will force any debris through the bleeder screw and make a clear path for the fluid to go.

Doing it with a hand vacuum pump probably isn't fun, but it works.

Pedal going to the floor for the first few pumps after changing pads is very normal. It's the caliper pistons extending out and making contact with the pads. As they wear, the fluid level in the reservoir will go down some, but don't waste your fluid topping it off. If you do, it'll just puke out of the reservoir the next time you compress the calipers to change the pads. Even with all brake pads worn, the amount in there will still be safe. Brake fluid is hydroscopic (it absorbos moisture), so it's best not to open the reservoir anyway unless you're servicing the brakes.

On to your root question: You'll need to visually inspect the caliper for signs of leakage. It may be a caliper, but it is just as likely to be the rear wheel oil seal. You'll need to look at it to see which it is. When you remove the rear rotor, you'll see the oil seal. It's not absolutely necessary to replace them in pairs, but it's highly-recommended. Similar to light bulbs - if one fails, the other one probably will soon so you might as well get it out of the way.

 

Thanks for your response and info. Since I typed that post I have researched further about the wet spot and ran up on Quintons' thread concerning the rear axle seals and bearings. The most interesting finding in my research is where someone stated that a axle seal usually starts leaking for a reason, and that reason is sometimes a axle bearing that has loosened up and is slinging oil at the seal. I'm not sure I am competent to inspect the bearing after the seal is out to accurately access issues. Will it be obvious if it is loose? I wish I knew from experience how to tell. I continue to look on forums and Youtube for answers. Thanks again.

 

What you read is often correct. And even if the bearing isn't bad, while it's apart is the time to change it. And I'd do it on both sides so you're not wasting $60 worth of gear oil down the road.

With the rotor off, you can try wiggling the axle up and down. If it moves, the bearing is bad. If it doesn't, replace it anyway since you'll already have it apart to replace the seal.

 

Thanks for the response. I have already ordered the seals. I am also going to order the bearings. It appears Rockauto does not sell the OEM replacement bearing. I'm wondering if the MC bearings are the ones to get.

 

I replaced only the right rear axle seal on my 2000 F150 at 80k miles and the other one was still doing well with 170k miles when my buddy sold it. I sold it to him at 105k.

 

I lost a rear seal on one side on my 97 F150 not long after I bought it in 2001 with 65k miles on it. I think the rear axle seal went out at lets just say 80k miles...

Well, I replaced both axle seals when I did it.. Didn't do the bearings.. They seemed fine.

I traded that 97 for my 13 in Jan 2014 and the 97 had some 255,000 miles on it at that time and had towed my TT since 2002 and I never had a bearing issue or another seal issue...

Just my experience with it.. YMMV..

Mitch

 

I've had it happen both ways. Sometimes replacing the seals alone got the job done, and other times it had to be done again after a few months or a year.

So now I just do the bearings and seals at the same time just to be sure.

Regarding brand, Motorcraft doesn't actually make bearings. I believe that SKF does. Just avoid the Chinese stuff and you'll be fine.