Rebuild the brake master cylinder instead of replacing the whole unit with the Dorman - First Stop Brake Master Cylinder Repair Kit TM13621. This direct-replacement kit is cataloged for a range of vintage GM trucks and vans, including the 1951-1955 GMC 100-22, 1952-1953 GMC 102-22, 1953-1955 GMC 150-22, 1956-1959 GMC 100/150/250/300, 1959 Chevrolet Truck, 1960-1966 Chevrolet P20 and P30 Series, and 1966 GMC PB2500 and PB3500 Van — see the Buyer's Guide tab for the full list.
The brake master cylinder converts pedal force into the hydraulic pressure that operates the brakes. Its internal rubber seals wear over time and can let fluid bypass inside the bore. If worn master-cylinder seals are the cause of a slowly sinking or spongy pedal, this kit supplies the replacement sealing components to reseal the cylinder.
Country of origin: Taiwan.
Interchange: 22989 · MK535040 · 5454427 · MK-146 · MK146 · F13621 · MK13621
Manufacturer part number TM13621.
This part cross-references / interchanges with the following part numbers:
What does this repair kit do?
It supplies the EPDM rubber sealing components used to rebuild the brake master cylinder, resealing the internal parts that let the cylinder generate hydraulic pressure.
Which vehicles does it fit?
It's cataloged for various 1951-1966 GMC and Chevrolet trucks and vans, including GMC 100/150/250/300, Chevrolet P20/P30 Series, and GMC PB2500/PB3500 Van. See the Buyer's Guide tab for the full list.
What bore size is this kit for?
This kit is for a brake master cylinder with a 1.125 in bore.
What are signs my master cylinder may need this kit?
A brake pedal that slowly sinks under steady pressure or feels spongy can indicate worn master-cylinder seals. Diagnose the cause before servicing, since other components can cause the same symptoms.
What interchange numbers does it replace?
It cross-references 22989, MK535040, 5454427, MK-146 (MK146), F13621, and MK13621.
WARNING: These products can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
