Caterpillar 594H questions

[JEVANS]

Hello,
I have been working on a Cat 594H as of late, because the Torque failed. So clean it up, and replace the Torque etc.
my questions relate to its normal operation.
Should the brakes be able to hold the machine easily against its own power? They hold solidly at low idle, but much more than that and it will drive through the brakes. It loads the engine up, but you can’t stop it.

Second does this machine steer with only the steering levers? Or do you have to use your feet on the brake pedals? Other Dozers I’ve ran can steer using only the hand levers, pull it a little to disengage power to that track pull it all the way to steer sharp. This one won’t steer with just the hand levers, you have to use the brakes if you want to steer sharp.
As far as I know, this machine is essentially a modified D9H, but if you know otherwise Im all ears.

Thanks

 

[nicky 68a]

Hello.
The 594H will steer without the brake pedals.
I like to be able to hold it still at full throttle in 1st gear.

 

[nicky 68a]

It’s not a 594G badged up as an H is it?

 

[JEVANS]

I dont know for sure if its a G or H, but the decals on it are showing it as an H.
Did the G’s not steer off of the levers only?

So if it won’t hold itself back under full throttle are the brakes toast?

I adjusted the brakes all the way till they touched down. It was 12 clicks for left side and 8 for the right side, then I backed off 4 clicks each. The pedals have a good feel, but I can’t push hard enough to hold the machine back even under 1/2 throttle

 

[Nige]

I dont know for sure if its a G or H, but the decals on it are showing it as an H.

If it's a 594H the Serial Number will start with 96V.

 

[JEVANS]

Yep, its serial number does start with 96V. So I guess it is in fact a H.

 

[JEVANS]

Does anyone know if these 594’s came with a De-accelerator pedal originally?
This unit does not have one, and they want it to have one. I can see why, it must be a handful to operate without one, trying to run throttle, steering, brakes, winches all at once, especially when the brakes wont hold it back under power.
There is no mention of Decel pedal in the O&MM, where it talks about operating the machine.

Does anyone have some information as far as installing a Decel pedal onto this machine? Is it something we can buy from Cat, or is it something Im gonna have to Fabri-cobble together?

Thanks for any advice

 

[Nige]

So if it won’t hold itself back under full throttle are the brakes toast?

Yes. I’d suggest to fix the brakes before proceeding any further. It may be that the lack of brakes is influencing everything else control-wise and making it overly difficult

 

[JEVANS]

Ok thanks Nige. Hopefully they want to spend the money on the old girl. Regardless, I think having a Decel pedal would still be ideal though. Even If the brakes hold I wouldn’t think it would be ideal to sit with the torque stalled for longer than necessary.

 

[Nige]

Even If the brakes hold I wouldn’t think it would be ideal to sit with the torque stalled for longer than necessary.

Even with a dozer setup equipped with a decelerator no half-decent operator would contemplate doing that if he wanted to keep his job. He'd flip the transmission control to neutral PDQ.

There is no decelerator setup listed for a 96V machine, period.
There are quite a few different governor control setups depending on Serial Number.
Pretty much those exact same governor control setups also appear in the 90V-prefix D9H tractor, so it ought to be possible in theory to modify what is on your 594H to make it the same as a 90V machine.

As regards the chance of buying parts from Cat, I think you're stretching the bounds of possibility with a machine that's at least 50 years old by now. Probably better to go looking for a 90V machine in a scrapyard and get the parts from it.

 

[JEVANS]

Sounds good. I appreciate the help, thank you.

 

[nicky 68a]

As Nige says,the world is full of scrapyards and finding breakers yards selling D9H parts should be easy.
You’ll also find many popular parts readily available from non oem manufacturers

 

[tctractors]

I tend to think in first gear above half engine speed the brakes would be struggling to hold, driving through the brakes would be the result, I do a stall test in the higher gears only and only do a shaft stop test in first gear, although it stalls the converter its only at low speed, the H series peddles are pendent hanging down from the front dash, G's are from below the floor plates, the Decelerator on the D9H is oil controlled rotating a control valve to open or close an oil port that feeds onto a piston, this would be a bit of work to install and best removed from another engine.

 

[Nige]

I tend to think in first gear above half engine speed the brakes would be struggling to hold,

I agree. Generally a stall test to check brake holding ability on a newer model would say something like “engage first gear, fully apply the service brake, accelerate the engine to X rpm, the vehicle must not move”. Problem is I have no idea what X would be for a D9H.

The nearest I can find quickly is for a modern-day D10T which requests:-
"Depress the brake pedal and release the parking brake switch.
With the brake pedal depressed, move the directional control lever to the SECOND SPEED FORWARD position. Gradually increase the engine speed to full load speed. The machine should not move."

EDIT: It goes without saying that the efficiency of the service brake on a D10T is far better than a D9H.

 

[Welder Dave]

I think even on my 931B(D3B) the brake test is in 2nd gear.

 

[Nige]

Here's the brake adjustment procedure in case you don't have a service manual.

 

[JEVANS]

Hey Guys,

I appreciate all the help everyone gave. Thanks for the brake adjustment procedure Nige! That’s awesome.
When I had it running this afternoon, I tried the test again, it will hold against full power in 2nd gear. The right brake seems to be worse than the left, really gotta put some hard pressure to get it to do much even at lower rpm. But together they will hold against full power in 2nd. The machine pretty much sits on Rig mats on flat ground all the time, so I doubt they will want to tear into it, but I feel its on borrowed time before it will need brakes.

 

[Nige]

Keep us updated if there is any improvement once you have the brakes adjusted.

 

[JEVANS]

I will do.