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Donald
Donald, Small Engine Technician
Category: Small Engine
Satisfied Customers: 2026
Experience:  I have 25+ years of experience repairing 2 & 4 cycle engines
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I have a 48 inch zero turn I replace the hydraulic pump

Customer Question

I have a scag 48 inch zero turn I replace the hydraulic pump thinking it was going bad then I replace the wheel motor on the right side I Purged the system it will drive right for 15 minutes it starts whining and jerky then I shut it off and after about 20 minutes I started put your arms forward and it won't go for a few seconds It like takes some time for the oil to get in the lines. Am I sucking air in somewhere or getting air in the lines constantly?
Submitted: 10 months ago.
Category: Small Engine
Expert:  Donald replied 10 months ago.

Hello. Thank you for choosing Just Answer. My name is***** will be happy to assist you.

Expert:  Donald replied 10 months ago.

Jason, you likely have an air leak. It could be at one of your fittings.

Expert:  Donald replied 10 months ago.

Look inside your oil reservoir. If your oil is foaming or has excessive bubbles, this indicates an air leak.

Customer: replied 10 months ago.
No foam or bubbles ever
Expert:  Donald replied 10 months ago.

Thanks for your reply. What about your drive belt? Is it in good condition, and as tight as it needs to be?

Expert:  Donald replied 10 months ago.

This is a troubleshooting question ...

Customer: replied 10 months ago.
It seems tight but a little oily
Customer: replied 10 months ago.
Not terrible thouth
Expert:  Donald replied 10 months ago.

Are you requesting a phone call?

Customer: replied 10 months ago.
that costs an additional 24 on top of 27?
Expert:  Donald replied 10 months ago.

Yes, you are correct. If you like, we can continue on this discussion page.

Customer: replied 10 months ago.
Yeah that's too pricey sorry
Expert:  Donald replied 10 months ago.

No problem. I prefer to continue on this page. Does your left side continue to perform well, after 15 minutes?

Customer: replied 10 months ago.
After it does start to go normally it'll drive good for 10 min then jerky again and I shut it down then 30 minutes later I pushed the arms forward and it won't engage right away but then it will and it's whining at first
Expert:  Donald replied 10 months ago.

Jason, I would like express a thought I have.

Customer: replied 10 months ago.
It seems lime whole hydraulic system starts getting whiny I don't know I'm too afraid to keep driving it because before I replace the hydraulic pump and the wheel motor I kept blowing the seal out of the bottom of the pump
Customer: replied 10 months ago.
your thought?
Expert:  Donald replied 10 months ago.

If a drive belt is slipping, it can sometimes noticeably affect only one side of your hydraulic drive. You stated that your belt is a little oily. If your belt is oily, it is possible that one of your pump pulleys are also a little oily. It is also possible that an oily belt, can begin to slip after it heats up.

Expert:  Donald replied 10 months ago.

A worn/slipping belt can reduce the performance of even a perfectly working hydro drive system ...

Customer: replied 10 months ago.
I suppose I'll clean the belt off and the oil up underneath since I didn't get it all off and maybe possibly just change the belt
Expert:  Donald replied 10 months ago.

As a process of elimination, I would clean the oil from your pump pulleys, and replace the drive belt.

Expert:  Donald replied 10 months ago.

If you had an air leak, you would likely see bubbles, or foaming inside your oil reservoir.

Expert:  Donald replied 10 months ago.

I would definitely purchase an OEM belt.

Customer: replied 10 months ago.
I do know after I change the right hand pump because of blowing the lip seal out of the bottom found out after changing it it wasn't the problem so I changed the right hand wheel motor and I just feel if I keep on driving it right now the lip seals going to blow again so I don't think I've ever really corrected the problem
Customer: replied 10 months ago.
The belt does kind of make sense though it just doesn't seem real oily but I never really have clean the oil off of anything
Expert:  Donald replied 10 months ago.

I would like to confirm something. You put in a brand new pump??

Expert:  Donald replied 10 months ago.

We can continue after you replace your belt. There are no additional fees for us to continue.

Customer: replied 10 months ago.
Cool I'll get back to u tomorrow and yes brand new rh pump and rh wheel motor
Customer: replied 10 months ago.
Well I cleaned off belt and sprayed belt dressing on it got to first yard and blew the right lip seal out of the pump????
Customer: replied 10 months ago.
After 5-10 min
Expert:  Donald replied 10 months ago.

Jason, I am back with you. Can you get the model numbers from your pump for me? I would like to take a look at your pump.

Customer: replied 10 months ago.
PG-1GCC-DY1X-XXXX
Expert:  Donald replied 10 months ago.

Thanks for these numbers. Your original pump blew the lip seal? Now your new pump has blown a seal too?

Customer: replied 10 months ago.
Correct. I changed wheel motor also on rh side
Expert:  Donald replied 10 months ago.

Can you give me a minute or two, to pull up a diagram of your pump?

Customer: replied 10 months ago.
Yesy
Expert:  Donald replied 10 months ago.

When you say blow seal, is the seal actually coming out of the pump, or is it just leaking oil really bad?

Customer: replied 10 months ago.
Around the pump shaft it blows out just inner part of seal understand?
Expert:  Donald replied 10 months ago.

I understand now. Due to the fact that you had this problem with both pumps, I am lead to believe that you still have air being sucked into your system.

Expert:  Donald replied 10 months ago.

You have either a hose or a fitting that caused the problem with your original pump.

Expert:  Donald replied 10 months ago.

There is a return hose that allows your oil to return to your reservoir. I would check this hose first.

Customer: replied 10 months ago.
Is that the lower hose?
Expert:  Donald replied 10 months ago.

Yes it is. Also, you want to check that hose for restrictions. Make sure that hose hasn't started to collapsed internally, and restricting your oil flow. A restriction in your return hose can cause pressure to build inside your pump.

Customer: replied 10 months ago.
Hose is fine
Expert:  Donald replied 10 months ago.

Did you remove it and check to see if it is restricted?

Customer: replied 10 months ago.
blew through it. Its fine
Expert:  Donald replied 10 months ago.

I know it is time consuming, but I would double check each hose and fitting. Pressure is definitely building in your pump.

Customer: replied 10 months ago.
Ok I'll get back to u
Expert:  Donald replied 10 months ago.

Thanks!

Customer: replied 10 months ago.
Okay the hose going from fitting next to dump valve on left pump to filter I grabbed a hold of that hose and down by the filter I could spin it. Does that one have to be extremely tight?
Expert:  Donald replied 10 months ago.

If your hose will spin, this could cause a problem. If it still spins, after you tighten it more, then it will need to be replaced.

Customer: replied 10 months ago.
How about o rings on pumps where the high pressure hoses connected
Expert:  Donald replied 10 months ago.

If you have not replaced the o-rings, I would replace them.