W126 - Brake Flush = Dragging Calipers?!
 

Okay last night I flushed the brakes on my 300SD and I've flushed brakes many times before on Domestic vehicles, the only thing I can think of that could be a problem is that during this process I failed to notify the person watching the master cylinder that there are two chambers within the reservoir. :o So the MS went dry on the front circuit...

So, do I need to bleed the master cylinder then go back and bleed each wheel again? :confused:

I was going to go cruise today... but not until I get this resolved. :( Thanks for any help guys!

Fill the MC reservior up to the very top and re-bleed the brakes on the circuit that went dry. I like to use a MitiVac for this, it's easier and will pull the air out better. You can still go dry, though.....

If you get dragging brakes after flushing, it's time for a caliper rebuild -- quite likely you disturbed all the crud lying on the bottom of the caliper bores and this can make the pistons stick.

At any rate, you are getting up to the age on that car where you need to do the calipers anyway, the rubber gets hard and stiff requardless of fluid changes or driving habits.

Peter

I just bled all 4 and was working well... then started dragging again! :mad: So back I go again to rebleed and see how that treats me.

If not, looks like I'll be out for rebuilt calipers. :(

When I get a dragging brake I always try to bleed first. If you are a cheap ass like me just take the caliper apart.
Disconnect the caliper and shoot some compressed air into the line inlet to pop out the piston. (CAREFULLY)
Take some emery cloth and rub the piston and inside of the caliper. Rinse with some brake cleaner and let it dry. Put it all back together and rebleed.