Front Disk Brake Calipers - Is some pad/disk contact normal?

Moderators: Sluggo, Amskeptic

Post Reply
User avatar
vwlover77
IAC Addict!
Location: North Canton, Ohio
Status: Offline

Front Disk Brake Calipers - Is some pad/disk contact normal?

Post by vwlover77 » Sun Jul 17, 2016 5:16 am

I've noticed a slight pull to the left when the brakes are just starting to be applied. Once I've corrected the steering slightly and press harder on the pedal, the braking action is even.

I jacked up the front of the Bus. The right front wheel spins completely freely with no sound of pads contacting the disk.

The left front wheel spins easily, but there is the sound of the pads rubbing on the disk, and the spinning wheel stops much sooner as a result.

I think I should start with the left front caliper, looking for any binding of the pads or a slightly sticky cylinder.

Would you agree?
Don

---------------------------
78 Westy
71 Super Beetle Convertible Autostick

"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: Front Disk Brake Calipers - Is some pad/disk contact normal?

Post by Amskeptic » Mon Jul 18, 2016 8:06 am

vwlover77 wrote:I've noticed a slight pull to the left when the brakes are just starting to be applied. Once I've corrected the steering slightly and press harder on the pedal, the braking action is even.

I jacked up the front of the Bus. The right front wheel spins completely freely with no sound of pads contacting the disk.

The left front wheel spins easily, but there is the sound of the pads rubbing on the disk, and the spinning wheel stops much sooner as a result.

I think I should start with the left front caliper, looking for any binding of the pads or a slightly sticky cylinder.

Would you agree?
If you have an unusually different of drag, I would go first to the pistons to see if one or both are sticking in their bores. Just take the pads out and see how easily the pistons retract. Note if one pad is skinnier than the other.

There is normally a little contact to help keep pads and disks dry in the wet. Your spreader spring has ramps to help drive the pads back after application. perform an inspection of the spreader springs, look for where they contact the pins and the pads and see if they are the same on the right and left sides.

Then take the bug.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
vwlover77
IAC Addict!
Location: North Canton, Ohio
Status: Offline

Re: Front Disk Brake Calipers - Is some pad/disk contact normal?

Post by vwlover77 » Mon Jul 18, 2016 8:04 pm

I checked out both calipers this evening.

The passenger side pistons pushed back into the caliper smoothly with what seemed to be equal force. Rubber bellows are in good shape. The pads both had the same amount of wear. I cleaned up all the pad / caliper contact surfaces with fine sandpaper, and did the same to the retention pins and ramps on the spreader spring. Finished it off with a very light application of disk brake grease to the top and bottom edges of the pad steel backings that slide against the calipers, spreader spring ramps, and pins.

Moved to the driver's side and found more wear on the inboard pad than the outboard one, and more wear on the outboard pad than on the passenger side. Hmmm. Curious. As with the passenger side, the pistons pushed back into the caliper smoothly with what seemed to be equal force. Rubber bellows are in good shape on this side too. There did seem to be more corrosion on the pins, pad steel backings, and spring ramps on this side. Maybe that corrosion was preventing the pads from fully retracting with the result of more wear??? Cleaned up and lubed everything identically to the passenger side.

I'll drive it as soon as possible and let you know the results!
Don

---------------------------
78 Westy
71 Super Beetle Convertible Autostick

"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen

User avatar
vwlover77
IAC Addict!
Location: North Canton, Ohio
Status: Offline

Re: Front Disk Brake Calipers - Is some pad/disk contact normal?

Post by vwlover77 » Wed Jul 20, 2016 4:16 am

I think it helped!
Don

---------------------------
78 Westy
71 Super Beetle Convertible Autostick

"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: Front Disk Brake Calipers - Is some pad/disk contact normal?

Post by Amskeptic » Wed Jul 20, 2016 8:27 am

vwlover77 wrote:I think it helped!
Good. Keep driving. These cars like driving.
Colin :compress:
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
vwlover77
IAC Addict!
Location: North Canton, Ohio
Status: Offline

Re: Front Disk Brake Calipers - Is some pad/disk contact normal?

Post by vwlover77 » Fri Jul 22, 2016 6:04 am

Amskeptic wrote:Keep driving. These cars like driving.
Every chance I get! It's pretty much my daily driver in the summer.
Don

---------------------------
78 Westy
71 Super Beetle Convertible Autostick

"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen

Post Reply