Hydraulic Brake Line Fitting Size Required for etrailer.com Replacement Wheel Cylinder # AKBRKR-H7-R

Updated 01/07/2025 | Published 04/30/2020

Question:

Does a 3/16inch hydraulic fitting screw into the wheel cylinder?

asked by: Patrick B

Expert Reply:

Yes, a standard 3/16 brake line fitting threads into the etrailer.com Replacement Wheel Cylinder, # AKBRKR-H7-R. If your trailer currently has hydraulic trailer brakes on axles ranging from 3,500 lbs to 7,000 lbs, then your existing brake line fitting will thread right in.

expert reply by: John H

Newell

1/3/2025

I wanted to piggy back on the answer that you gave regarding the thread size for the AKB RKR-H&-R wheel cylinder. I have a 1987 EZLoader trailer that needs new wheel cylinders. I recently purchased a Dorman W36074 cylinder that fits perfectly except for the brake hose fitting. The Dorman cylinder appears to have a 7/16 inch thread and my trailer appears to have a 3/8ths thread size. Do you have a replacement wheel cylinder that has a fitting size of 3/8ths? AS an alternative do you have thread adapters that would allow your cylinders to fit my brake line fittings?? Any advice would certainly be appreciated.....newell

John H.

1/7/2025

@Newell I can tell you we don't have any wheel cylinders that will accept a 7/16 thread and we don't have an adapter that will work with our cylinder or a 3/8 threaded cylinder, but I'm curious to know more about what exactly you have. Is there any sort of brand marking on your brake assemblies or weight capacity? You might be better off checking for an adapter from an auto parts store or an industrial supply/fastener store. They will have a much wider variety, and our selection is more limited to trailer and RV applications and a lot of the parts used on trailers made before the 90's are discontinued and pretty hard to find if they weren't common automotive parts.

Newell

1/7/2025

@JohnH : Thanks for the reply. Jus to be clear....I ordered the Dorman wheel cylinder because it looked like the correct one for my trailer. However my fittings are 3/8 x 24 and the Dorman cylinder was 7/16 x 20....so did not fit. I think the best course of action for me is to rebuild the cylinders that are original on the trailer. As spring comes around I will check beck with you for the correct rebuild kit ...IF...I can identify the brake assembly manufacturer or the wheel cylinder manufacturer..........thanks again newell