Stuck Caliper. Help!

cutecumber

New member
Need brake help. Front driver side brake caliper is stuck. Pistons won't release. Test drive around the block equals red hot brakes.

What we've done: install new caliper, replace brake hose, checked break lines, bled brake lines, installed new brake pads.

Any ideas for what to do next?
 

Aqua Puttana

Poly - Thread Finder
Need brake help. Front driver side brake caliper is stuck. Pistons won't release. Test drive around the block equals red hot brakes.

What we've done: install new caliper, replace brake hose, checked break lines, bled brake lines, installed new brake pads.

Any ideas for what to do next?
Was the front driver side caliper stuck prior to installing the new one, or was the caliper replaced for other reasons?

New parts, and especially rebuilt parts these days, can be bad out of the box.

After removing the caliper you can try carefully to have someone press lightly on the brake pedal while you watch the movement of the pistons. Then make certain that they compress back easily. Be aware that with dual pistons one piston may move out more quickly than the other.

:cheers: vic
 

cutecumber

New member
Used genuine MB parts. Just disconnected the brake hose and opened the bleeder valve and the caliper opened right up.

Will check the caliper pistons now as you described.

Maybe it could be the master cylinder?
 

cutecumber

New member
Yes the caliper was stuck before installing the new one. Thought replacing the caliper would fix the issue but didn't. Same for the brake pads. Didn't need replacing but replaced for good measure.
 

autostaretx

Erratic Member
Also check the anti-lock brake lever and "controller" ... when the van "jacks up", a mechanical linkage (in the rear) operates a proportioning value which controls the distribution of brake pressure between the front and back of the van.
(see "ALB" in the service manual ... or just follow the brake lines to find it).
I can't see how/why it would only affect *one* front caliper, but leave no stone unturned.

--dick
2006 service manual, chapter five: http://diysprinter.co.uk/reference/2006-VA-SM.pdf
 

gs850gx

Member
So just to be clear, your caliper was not releasing unless you opened the bleeder. You then replaced the caliper and hose and the new one won't release until you open the bleeder?
 

Nautamaran

2004 140” HRC 2500 (Crewed)
I’d trace the issue further upstream? Try cracking open the brake line at the master cylinder, then the ABS block outlet. This will at least locate the point of restriction.
My guess is that a valve within the abs system is sticking and holding pressure, but I’ve never had one apart so don’t know how that may happen.
Is the diagonally opposite wheel also holding pressure? If so look at the m/c. Just the one wheel? ABS block.

-dave
 

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