Brake issue on Ford 4500

don humphrey · Mar 6, 2025

Hello, I have a 1975 Ford 4500 forklift (same as the backhoe I think), anyway the brake pedals go right to the floor 90% of the time and there is very limited brake power however every once in a while the brake pedal will kick back and suddenly it has great brakes, sometimes it seems to be when it's running at a higher RPM.
My question is does this model have some kind of power brakes (vacuum or hydraulic) and if so should I be looking for a vacuum line issue or hydraulic reservoir that is low on fluid? It doesn't seem to be a pedal adjustment issue because when they do kick in they work great and the pedals seem like they are at about the correct height (about 50% of the total travel).
Thanks for your help.

Harry in Ky · Mar 6, 2025

Not being familiar with a forklift version of this tractor I can't really visualize how the brake pedals and linkage would be set up. Assuming the seat, steering and other controls are reversed and are mounted on a platform of sorts, the linkage must a few more parts and pivot points than the straddle mount tractor models. It seems strange to me that an internal brake problem would affect both sides at the same time with both not working then suddenly working again.

That said, on the tractor versions pedal travel at (or near) half way on total travel would be too much in my opinion. I usually adjust the brakes so the travel is more like one third or less of total travel. Are there any adjustments in the linkages anywhere other than on the brake shafts themselves? (the rods going into the brake housings)

joecdeere · Mar 7, 2025

Those should be wet multi-disc brakes the disc are applied by the “twisting”of two plates with balls running in a ramp. Kinda sounds like the balls are not always returning to the released position. Hopefully others with more hands on knowledge will be here soon.

TractorTech · Mar 10, 2025

Welcome to TBN!

What brand is the forklift?

don humphrey · Mar 18, 2025

TractorTech said:
Welcome to TBN!

What brand is the forklift?

As far as I know it is all Ford, they used the 4500 tractor chassis as a base for the back hoes and forklifts.

don humphrey · Mar 18, 2025

Harry in Ky said:
Not being familiar with a forklift version of this tractor I can't really visualize how the brake pedals and linkage would be set up. Assuming the seat, steering and other controls are reversed and are mounted on a platform of sorts, the linkage must a few more parts and pivot points than the straddle mount tractor models. It seems strange to me that an internal brake problem would affect both sides at the same time with both not working then suddenly working again.

That said, on the tractor versions pedal travel at (or near) half way on total travel would be too much in my opinion. I usually adjust the brakes so the travel is more like one third or less of total travel. Are there any adjustments in the linkages anywhere other than on the brake shafts themselves? (the rods going into the brake housings)

It does not seem to be an adjustment issue as it comes and goes, a simple adjustment issue would be the same all the time.

TractorTech · Mar 18, 2025

Ford didn't make any forklifts, but many forklifts used the Ford drivetrain. Harlo, Master Craft, KD Forklift and others were some. If it is a 4500, then it is all linkage, but some may have used hydraulic actuated brakes on the Ford axle.