Turn brake-pedal pressure into shoe-to-drum force at the rear with this Dorman drum brake wheel cylinder, part number W37644 from the Dorman - First Stop line. It fits many vehicles, among them the 1982-1988 Chevrolet S10, 1983-1988 Chevrolet S10 Blazer and 1982-1988 GMC S15. See the "Vehicles it fits" section for the full list and engine details.
The wheel cylinder works inside the rear drum brake assembly. Hydraulic pressure from the master cylinder drives its pistons outward to press the brake shoes against the drum. Dorman engineered this direct replacement to match the original wheel cylinder's fit, function and performance on the listed applications. Each unit is manufactured and tested for quality assurance.
- Ideal replacement: engineered as a direct match for the original drum brake wheel cylinder on the listed applications.
- Cost-effective fix: replacing the cylinder while the drum brakes are already apart is a quick, economical step during a brake service.
- Quality materials: built with high-quality EPDM rubber cups and boots.
- Professionally tested: the cylinder bores are surface-tested to help provide an optimum sealing surface for the pressure cups.
Signs a wheel cylinder may need replacing include brake fluid seeping at the drum or backing plate, a soft or sinking brake pedal, and uneven rear braking. Each side of the axle has its own wheel cylinder, so replacing both sides together is recommended for balanced braking. Bleed the brake system after installation.
Interchange: 784-44016 · 84-44016 · 101-1642 · W-86016 · 134.66016 · 135.66016 · 375-47069
78444016 · 8444016 · 1011642 · W86016 · 13466016 · 13566016 · 37547069 · 18E239 · W906558 · 33892 · WC13892 · WC370267 · F110261 · WC110261
This part cross-references / interchanges with the following part numbers:
18E239, 784-44016, 84-44016, W906558, 101-1642, W-86016, 33892, 134.66016, 135.66016, WC13892, 375-47069, WC370267, F110261, WC110261
Frequently Asked Questions
What does a drum brake wheel cylinder do?
It uses hydraulic pressure from the master cylinder to push the brake shoes outward against the drum. W37644 is a rear wheel cylinder made with EPDM rubber cups and boots.
Is this Dorman part right for a 1982-1988 Chevrolet S10 wheel cylinder replacement?
W37644 is listed as a rear drum brake wheel cylinder for the 1982-1988 Chevrolet S10. Check the "Vehicles it fits" section to confirm the match for your truck.
Does it also fit the 1983-1988 Chevrolet S10 Blazer and 1982-1988 GMC S15?
Yes. It is listed for the 1983-1988 Chevrolet S10 Blazer and the 1982-1988 GMC S15. The "Vehicles it fits" section has the full application list.
What are signs a wheel cylinder may need replacing?
Common signs include brake fluid leaking inside the drum or at the backing plate, a soft or sinking pedal, and uneven rear braking. Diagnose the cause before you replace parts.
How are the cylinder bores tested?
Dorman surface-tests the wheel cylinder bores to help provide an optimum sealing surface for the pressure cups. Each unit is manufactured and tested for quality assurance.
