550G Steering Pedals

[Bmp4510]

Hi,
I recently bought a 550g, direct drive pedal steer. Kinda of an odd tractor, has the tracks spaced out and 10.5’ blade for LGP, but with 18” pads. (Dreams of grandeur have me thinking I will someday put the wider pads on her, but realistically it’s doubtful.) I did purchase the operating, test and repair manuals.

Anyway I live outside of Hilo Hawaii, so machines and parts are pricey and rare here. The issue I have is the right turn brake pedal doesn’t return to the neutral position, and you have to pull it up to release the brake and engage the right clutch.

Previous owner had ordered new pedal return springs and gave them to me. I removed the panels and was hoping to find debris impeding the travel of the brake rods. While not spotless, nothing seems to be in the way debris wise. Previous owner had installed an aftermarket extra spring to assist with the return of the pedal.

After removing the various panels, I depressed and lifted the pedal to observe the rod and lever movements. At rest, the right pedal is 2” lower than the left, guessing 6-8” from dash/floorboard. Pulling the pedal up, it required 20lbs effort or more, and went up 8” or so. After the pedal was in the up position, when it was released it returned downward to 2” below the left pedal. It was if a spring had pulled it back down.

Pulling out the test manual, I see that under the transverse cover are two large springs that run crosswise to the dozer, and would appear to be the springs I feel pulling the brake pedals to their current position. Is that correct?

Should I attempt the “Procedure for Complete Steering Adjustment” as described in the test manual?

The machine has 5000 hours on it. What is the typical hours the brakes will last? If brakes are worn out, would that case the pedal issue?

I pulled the plugs on the transverse case to inspect the brake adjusters. At first I thought I found the problem as the left side adjuster was plainly visible, while the right side wasn’t. But after reading more and looking at it, it appears the right adjuster is still intact and somewhat hidden by the threaded rod. The right side adjustment had double the amount of threads showing compared to the left side adjuster.

Any help is greatly appreciated. Thanks for reading.

[Jim B]

Welcome to the Boards.

I will admit I have no hands-on experience with the 550Gs. They are a different driveline than the vintage machines generally discussed here, mostly prior to the 350D/450D models. So don't be surprised if you do not get much for responses.

That said with any crawler, having steering problems, after a visual inspection of all visible linkages the next step is a full adjustment of the steering and brake system by the book. That means all steps, in the order given. JMHO

Good luck with this.

[Bmp4510]

I had a chance to tinker with the 550 that last few days. To do the entire brake/clutch adjustment two hydraulic pressure gauges are required, which I don’t have. But I decided to do just the simple brake band adjustment, so I backed the band out, then reset it. Darn thing actually started working properly for 95% of the time! Guessing the best thing would be to acquire some gauges to calibrate the valve body that releases/engages the clutches. But she’s significantly better now.

[Jim B]

Pressures are very important in hydraulic control and drive systems, so you are going to need them going forward.