i have some critical problem on CAT DOZER D8R MODEL

This topic contains 4 replies and was last updated by abhay 10 years 3 months ago
May 31st, 2011 10:32am
My Dozer being stering locked so, i have already check-in following jobs:

1. Stering Pump = it is ok

2. Hyd. Pump = it is also ok

3. Stering Control Valve = to be checked.

I couldn't find out the fault therefore what will be the cause of stering locked.plz help me if you have any idea abt. this problem

June 20th, 2011 7:23am
What is the serial number prefix on your machine? (three letters or numbers before serial #, example: 7ps)

Is there any recent repair history on your machine?

Is your machine covered by an oil sampling program? Have the final drives, hydraulic and steering system oils/filters been checked for debris or contaminents?

If one of the final drives is inoperative, has it been inspected? After checking final drive oil for metal, pull the final drive axle with the sun gear on it and inspect for damaged splines or sun gear.

Please clarify your complaint. When you wrote "steering locked" do you mean it will only turn in one direction? Or only straight ahead with no turning capability?

How did you eliminate the hyd. and steering pumps as possible causes? Did you perform pump output flow testing and case drain flow testing?

Keep in mind that the machine's braking system might be a possible cause. I'll have to double check this, but the brake disc packs in the rear axle powertrain are probably spring applied, pressure released, and therefore a leaking piston seal in the brake pack would cause the brake not to release. If that were to occur, would the leakage oil overfill the final drive or go elsewhere? There's probably a brake valve with some pressure taps on it for pressure testing the brake system but I recommend looking into the simpler diagnostic checks mentioned above first.

Is there a diagnostic lamp on the dash that's lit? I'll have to check SIS to determine what level of electronics, if any, this machine has on it.

Have any operational hydraulic or steering cycle time tests been performed? I'll have to double check this on SIS but I believe the steering system has it's own cycle time test. Have you noticed a low power or slow condition with the dozer and ripper functions?
July 6th, 2011 6:18am
electronexciter: Very impressive with your analytical skills. Keep it up.
February 23rd, 2012 3:40pm
I have an experience with steering system on D6R.

The D6R can't turn. it move straight only. When I check the pressure of hydraulic pump, it enough to operate all function but steering need bigger pressure. about 4500 psi. I check and found an spool at hyd control valve had broken. that was problem.

So I think U should check system pressure first then decide next step.
May 13th, 2021 9:42pm

My dozer steer fall to tuen

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