Master Brake Cylinder Rebuild

[Andres G]

Hello All,

Been away for a little while, but I'm now back for good (I hope). My SL has been running great and needing nothing but a little TLC and some consistent driving after I replaced the electric fuel pump last spring.

I am now thinking I want to take care of the brakes, which have been an issue for sometime in the past but I had not paid much attention to, considering I didn't drive the car too often. I understand that my problem is the master brake cylinder, and possibly the brake booster.

Anyone have any pointers, suggestions, ideas as to who rebuilds these and how much should it cost to get this done? I can take the pars out of the car and mail them, but want to know what I'll be facing before I get into this.

Thanks in advance for any and all help.

Andres

[Larry & Norma]

It may be useful to state which car you have. 230,250 or 280SL

[Benz Dr.]

I never rebuild brake master cylinders unless there's no other option. You have one, it's called a new one.

[Andres G]

Hey All,

I apologize... I tend to believe that since these forums are small, everyone knows which car everyone else has. In my case, I have a 1967 250 SL, Euro with a 4 spd.

The symptoms I have right now are two:
- Engine revs up when pressing hard on brakes with car idling
- I believe I am beginning to notice less braking efficiency on the passenger side front caliper... I not only notice it is beginning to pull to the left under hard braking, but I also noticed almost no brake dust on that side, while I can still see a visible amount of it on the opposite side.

Benz Dr, would you be able to point me towards a place where I can source a new one? What should I expect to pay?

Thanks,
Andres G

[Alex D]

I also have a 1967 250SL, 4 speed in need of new master cylinder.  Prefer not to rebuild.  Please let me know if you find a source for them.

Thanks,
Alex D

[Jonny B]

This was a problem for my car also, and I sourced the brake booster out of K&K. This was early this year, and the cost was around $400. Check with Dave Gallon, his prices for this kind of thing are hard to beat.

[mdsalemi]

http://www.mbpartswarehouse.com/parts/?N=11128+4294962557+1668+11921+9182

Three brands: remanufactured A1 Cardone & new Beck Arnley, new ATE.  See page for part demarcation at VIN -2980.

I found similar parts and prices in stock at several places.  Prices vary between $42 and $300 plus depending on brand and VIN.

[dirtrack49]

I give up, why not rebuild the master cylinder? Are there not any rebuild kits available for these cars?

If the cylinder bore is in reasonably good shape and can be honed out, why not do that and put in new seals?

Since I am trying to bring a 66 230sl back to life, I am sure I will need to replace or rebuild many items on this vehicle.

In the past, with several other types of cars, I have been successful at rebuilding masters, wheel cylinders, clutch cylinders and the like. Why would these cars be any different?

Not trying to be controversial, but curious as to the R&R versus a rebuild.

Tom L.

[ejboyd5]

Andres:  From what you've posted, I wouldn't start with the master cylinder or the booster unit since you seem to be getting appropriate action from both.  Start with replacement of the flexible brake hoses that service the wheels.  Check the caliper which you suspect is inoperative to make sure that the pads are not frozen in place from lack of exercise.  If rebuild of any component, i.e., wheel cylinder or master cylinder, is necessary there are many fine shops available to provide this service at modest cost with rapid turn around of your unit.

[ja17]

Hello Tom,

It is not normally an option for a shop to rebuild master cylinders these days. Most MB dealers charge over $100.00 dollars an hour and the kit most likely lists for around $60.00. With the risk of liability of brake failure due to a mistake by the re-builder, it does not make sense.  A new unit is around $200.00 plus or minus.

It can be an option for the do-it-yourselfer if you are diligent .  In years past it was a quite  common procedure when labor was cheap, frivolous litigation was less common and the world believed in rebuilding things instead of just replacing them.

Someone sold acomplete NOS master cylinder at the PUB 11 swap meet for $50.00.   

Lots of options out there. You may want to review the re-build procedure before you decide.