Pump problem

[FastLaneCarWash]

Hey guys I haven’t been on in a while I’ve been stuck out of town for work and it’s hard maintaining a car wash and traveling at the same time but here’s my dilemma. I have general pumps for my hp and one bay is pulsating pretty bad when rigger is pulled. If I let the trigger go it seems to build up pressure. I’ve never rebuilt a pressure washer pump. At work we sometimes work on pumps used for frac and downhole work “oilfield”. So we change out packings. So I removed some of the parts from the general pump just to observe what was inside. I inspected the o rings and the check valves if that’s what they are called and everything looked fine. I reassembled and turned on and same thing. So I found a diagram and a parts list and am curious what you guys think I should replace. I’m thinking I definitely at least need the number 1 kit. Do y’all think I should go ahead and get 3 of the number 29 kits also? Thanks for any help y’all.

On a side note what should I do to maintain these pumps. Should I do a schedule and replace them let’s say every year or wait until I have an issue and rebuild them then?

 

[Waxman]

I had a pulsation problem on a CAT pump and it was debris in the valves. Even a small amount of dirt /grit can cause bad chattering. Maybe order all the parts and then try the easy things like valves first.

 

[MEP001]

Here's the correct data sheet:

http://www.general-pump.net/PDFs/T921-Pump.pdf

It probably needs a seal kit. Be sure to inspect inside the manifold for washout where the seals sit. There's not a kit for just the seal parts, so you'll need a kit 148, half of a kit 11, and three 90.3616.00 o-rings. The valves almost never fail but the plastic cages tend to deform. I replace them if the valve doesn't stay together. You can throw in three kit 29's but those brass parts included in them don't usually go bad. You can save that money for a seal extractor tool in case you need it.

If you rebuild the pump immediately at the first sign of pulsation or weak pressure, you most likely won't have a problem, but it's important that the pump isn't running faster than it needs to. Keep in mind that if you're running 3 GPM at the bay but the pump is moving 4.5 GPM, that's 1-1/2 gallons per minute moving through a bad seal before there's a loss in pressure, which will erode and ruin the manifold.

 

[FastLaneCarWash]

Here's the correct data sheet:

http://www.general-pump.net/PDFs/T921-Pump.pdf

It probably needs a seal kit. Be sure to inspect inside the manifold for washout where the seals sit. There's not a kit for just the seal parts, so you'll need a kit 148, half of a kit 11, and three 90.3616.00 o-rings. The valves almost never fail but the plastic cages tend to deform. I replace them if the valve doesn't stay together. You can throw in three kit 29's but those brass parts included in them don't usually go bad. You can save that money for a seal extractor tool in case you need it.

If you rebuild the pump immediately at the first sign of pulsation or weak pressure, you most likely won't have a problem, but it's important that the pump isn't running faster than it needs to. Keep in mind that if you're running 3 GPM at the bay but the pump is moving 4.5 GPM, that's 1-1/2 gallons per minute moving through a bad seal before there's a loss in pressure, which will erode and ruin the manifold.

Where do you recommend getting these parts from?

 

[MEP001]

Windtrax if you're signed up for their free shipping. Kleen-Rite's prices are a little better but shipping from them is getting out of hand, and they'll most likely send you some of the parts and backorder the rest so you'll get double-dinged on freight. Windtrax (and most other suppliers) will follow your instructions if you ask them to ship the order complete.

 

[FastLaneCarWash]

Windtrax if you're signed up for their free shipping. Kleen-Rite's prices are a little better but shipping from them is getting out of hand, and they'll most likely send you some of the parts and backorder the rest so you'll get double-dinged on freight. Windtrax (and most other suppliers) will follow your instructions if you ask them to ship the order complete.

Awesome thanks as always MEP. I’m interested in expanding this location and installing a mini and Also I’m looking to expand on purchasing another car wash in a neighboring town. So I’m not going anywhere and you will see more posts from me in the future.

 

[traveler17]

You can also call a GP tech. Very helpful years back when I replaced a hp seal kit. #651-454-6500

 

[FastLaneCarWash]

You can also call a GP tech. Very helpful years back when I replaced a hp seal kit. #651-454-6500

Do you have a name for this guy?

 

[traveler17]

Do you have a name for this guy?

no sorry but when I called I just asked for tech support

 

[MEP001]

You can also call a GP tech. Very helpful years back when I replaced a hp seal kit. #651-454-6500

I am every bit as qualified as anyone at that number, as I was factory trained in GP service and have rebuilt many hundreds of them.

 

[traveler17]

I am every bit as qualified as anyone at that number, as I was factory trained in GP service and have rebuilt many hundreds of them.

i wasn’t implying you weren’t

 

[traveler17]

Just letting the gentleman know what I had done in the past before finding this forum

 

[FastLaneCarWash]

I am every bit as qualified as anyone at that number, as I was factory trained in GP service and have rebuilt many hundreds of them.

Hey MEP where do you recommend me getting the extractor tool and what size wil I need? I found a kit that does like 13mm to 24mm will that work? I took the pump apart and this is what I found. Nothing looks washed to me.

 

[Rfreeman]

Fast hard to tell from the pictures if you have any wash out in that pump head or not. But here is a pic from my cat head where its easier to see. For comparison I added a resleeved head as well. You want a nice smooth surface so the seals sit in there nice in clean

 

[MEP001]

It would be washed out under the valve o-rings (Probably not since the o-rings are intact) or where the packings seat. You haven't removed the packings, sometimes you can just pull them out by hand, but if they're corroded in you need the extractor.

Packing Extractor Kit for 13-24mm Packing | General Pump | 100783

Versatile packing extractor kit works with all General Pump models featuring 13mm - 24mm packing. Get it today at a the lowest pricing around from Kleen-Rite!

www.kleen-ritecorp.com

 

[FastLaneCarWash]

It would be washed out under the valve o-rings (Probably not since the o-rings are intact) or where the packings seat. You haven't removed the packings, sometimes you can just pull them out by hand, but if they're corroded in you need the extractor.

Packing Extractor Kit for 13-24mm Packing | General Pump | 100783

Versatile packing extractor kit works with all General Pump models featuring 13mm - 24mm packing. Get it today at a the lowest pricing around from Kleen-Rite!

www.kleen-ritecorp.com

Yeah those suckers are in there. I’ll order the extractor kit tonight and get them replaced and I’ll probably go ahead and order new packings for my other 5 pumps and replace just to have a baseline of when they have all been replaced and serviced.

 

[FastLaneCarWash]

Ok so I replaced all the soft seals and the check valves and it does the same exact thing. I’m going to switch the unloader/regulator with another known good one and see if that helps any. It’s almost as if it’s starving for water. Once weep is primed up it sprays without any pulsation but once the trigger is pulled it sprays hard and pulsates a second or two later. Any advice would be greatly appreciated.

 

[MEP001]

Fix this leak first. It could be your whole problem.

 

[FastLaneCarWash]

Fix this leak first. It could be your whole problem.

View attachment 2191

I think it’s wet from me removing the pump head but I will run over there and verify it is not leaking.

 

[FastLaneCarWash]

I think it’s wet from me removing the pump head but I will run over there and verify it is not leaking.

Yes that leak was just from taking the pump head off. It is completely dry?