Info needed: M38A1 Master Cylinder Replacement?

[Les Kovacs]

Hello to all.....I have a 67' M38A1 that requires a master cylinder replacement.

Not sure how it can be done but .....how do you take out the long bolt 3.5 inch bolt to rear of the master cylinder closest to the pushrod....screw it out an inch and it hits an engine bolt frame with at least another 2.5 inches of bolt to go?
Do any other parts have to come off....maybe pull out engine?

Also.....OR.....can I just replace the push rod and associated hardware from a rebuild kit without taking off the actual cylinder? If so, can I take a piece of fine sandpaper and sand the rust off of the (inside) master cylinder where the pushrod goes into the cylinder.

Please help,

lesk

[Owen Evans]

The setup on the M38 is the same. You need only to undo both bolts holding the master cylinder to the chassis. If the brake lines, cables and pedal shaft have all been disconnected, then the master cylinder should swing down on the tie bar, with both bolts still in place. In theory.

The attached should help..

Owen.

[charlie fitton]

They come out a certain distance, and are removed with the brake cylinder

[rob love]

You only have to back those bolts out a bit. As mentioned, have the bolt off that holds the brake lines, the vent line (if it's still there), and remove the cotter pin and washer at the crosshaft that holds that side plate on. The sideplate will come off with the master cylinder....with the two bolts backed off as much as you can, it all drops down. Or you can leave the cotter pin alone and swing it all down as a unit.

You will, with a 99.999% certainty, not get away with slipping a rebuild kit into a used master cylinder wile still on the frame. Besides, new masters are so cheap, why would you bother?

[Les Kovacs]

Wow....thanks Rob, Owen and Charlie....I will attempt it tonight.

With only a .001% chance of replacing the worn parts with a rebuild kit with the cylinder still in place I think I will put in new cylinder that I do have with the instructions as provided.

Best regards,

lesk

[rob love]

Originally Posted by Les Kovacs

Wow....thanks Rob, Owen and Charlie....I will attempt it tonight.

With only a .001% chance of replacing the worn parts with a rebuild kit with the cylinder still in place I think I will put in new cylinder that I do have with the instructions as provided.

Best regards,

lesk

That .001 % is actually a bit optimistic. I don't want you to think that there is a chance it could work.

[Les Kovacs]

Thanks to all.....Rob.....I followed your directions to a "T" and it was easier than anticipated to take off master cylinder and associated parts....many thanks again.

I installed a new master cylinder that I had from while back. I do have a master cylinder rebuild kit....would you install it on the master cylinder I just took off as a spare?

Best regards,

les

[rob love]

Personally, I wouldn't bother. Your brand new one should last 7 to 15 years.....by then your rebuilt one sitting on the shelf and drying out will be garbage again. As well, if your old one is pitted, you have to hone it to get rid of the pitting....dimensionally it is going to be out.

Brand new master cylinders are $50 from Rock Auto....possibly even cheaper on ebay. When you look at the price of the rebuild kit ($42.18 at NAPA) why would you want the lack of reliability of a rebuild?

The only exception to the above is if you had a fairly new cylinder that got contaminated and swelled up the rubber. In that case, if the bore is good, a rekit will (almost) make sense.