I am having trouble trying to push back the brake piston to install new brake pads. I do not want to force anything. I have tried leverage but I cannot get any movement. I could try a C-clamp but am worried about using too much force.

Is there any way to relieve the pressure to make it easier ? I thought there might be a bleed valve on the caliper, but there is only a threaded straight connector from hose to the caliper - nothing to which for instance a bleed hose could be attached. So how do you bleed these brakes ?

The caliper is a large single piston type made by LUCAS.

Someone on this forum suggested clamping the hose and opening the bleed valve to ensure no dirt in the hydraulic fuel goes back into the ABS, but there does not seem to be any bleed valve, so that I cannot even do that.

Any suggestions please ?

Have you worked on brakes much before? Sometimes it takes a good amount of force. And you need to be sure to push evenly on the piston so it doesn't bind up (don't just push on one side of it). I use a big channelock pliers with electric tape wrapped thick around the jaws. And I put it so it is even on the face of the piston. You can also get a special tool with two plates that spread apart. Are you working on the front or back? The back are a little different than "normal" in my opinion.

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Thanks. No, this is the first time !

I guess I have to try the C-Clamp then.

It has to have a bleeder valve and you are going to have to find it to bleed your brakes when you are done. I am not trying to slam you but I am a bit worried for your safety and fellow drivers' safety if you are working on your brakes and cannot find this. Maybe you need to find a shop to help you out?

http://www.benzworld.org/forums/w202-c-class/1201406-brake-job-99-c280.html

http://www.slk32.com/pages/brakes/brakes.html

I'd try the C clamp. It took me a fair amount of force to back the caliper off - couldn't have done it by hand. Just be sure to go SLOW and to open the master cylinder reservoir. Watch for overflow - use a turkey baster to remove fluid before it spills over.

Sometimes they get quite a bit of dust and dirt around the piston, making it hard to compress. I use large channel locks and the old inner pad to compress the piston. On occasions when really tough, C Clamp. If it still doesn't compress, then you will need to replace the caliper - it is frozen.

Best of luck.

Just take it slow and easy and be gentle. Pry against the old pads. After you get one side out, block the space with a new pad and pry/push the other piston back. Take your time and get the pistons pushed all the way back and then the new full width pads will slip right in. Sounds like you are having the same problems I had with my first brake job. It was "pry and try" (fitting new full width pad), "pry and try", over and over again, until I finally figured out I didn't have the pistons pushed all the way back. I do have one of those generic tools by Lisle but it doesn't fit well on this particular caliper. Watch your fluid level in the reservoir. Cleaning up spilled brake fluid is a real pain. No need to fiddle with the bleeder. This is only if you decide to flush brake fluid.

Sounds like your first brake job. You might have an experienced friend watch over your shoulder.

glenmore
1991 300CE
2000 C280
1990 LS400

Yes, channel locks work great.

Yes, DO bleed each caliper before removing the old pads. This will assure no spillover at the reservoir when the pistons are pushed in. Besides, this is the easiest way to bleed the line - while the wheel is off.

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