SoCal Jet Boats
Tech Talk => Jet Pumps => Topic started by: Patch on June 02, 2014, 08:54:15 AM
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While I was launching my boat 20.5 Advantage Classic closed deck AT-309 pump I fired it up as I was backing into the water I heard a large rattle and vibration from the jet. My son and I pulled it apart this weekend and found that the isolator rubber was missing and the wear ring was floating around. On the prior trip while I was greasing the pump I noticed my zerk for the bowl bushings was missing. I don't know how long it was missing. I replaced it and lubed the bushings. On inspection when I disassembled the pump the bowl bushings are also wasted and egged shaped. The end of the shaft is tore up. I already have the shaft repair kit on it so that should be a easy repair. The impellar is amazingly not in bad shape except were the area fits into the wear ring. How do I check the suction housing to be sure that the wear ring will still be centered? Or if it will even hold the wear ring snug enough? My bowls leading edges on the stator vanes are very worn and looks like I might need a bowl. Any advise will be greatly welcomed. I will try to post pictures tonight of the bowl and suction housing when I get home from work.
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What probably happened is that the worn bearings allowed the impeller to hit the wear ring, which caused the wear ring to spin burning up the isolator. Same thing happened to me with a freshly rebuilt pump that had been assembled with too much runout in the rotating assembly and loose fitting bowl bushings.
If I was you, I'd pull that whole pump apart and put the rotating assembly between centers or on some V-blocks and check runout on all critical points...make sure you are zero'd on each end, and make sure the impeller pilot (where it goes in the wear ring) is less than .003" or so. And put in a new thrust bearing, regardless of what else you do.
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Do you think that the wear ring spinning in the suction housing would cause any alignment issues?
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Depends if it hit the suction housing....mine ate it up pretty good
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Did you have to replace the suction housing. How do you check it. Do you reinstall every thing with new parts and spin the shaft and check for clearance? What if material was removed by the wear ring spinning, is there a thicker isolator to take up the difference?
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I replaced mine because I couldn't get an answer on the wear ring bore spec from anyone, so I had no idea if it was bad or not. I wanted it perfect. I ended up ordering an Ultimate wear ring from HPT .. http://www.hi-techperformance.com/images/Ultimate_Wear_Ring.jpg (http://www.hi-techperformance.com/images/Ultimate_Wear_Ring.jpg)
They're plastic...like a urethane, and the free diameter is about 1/2" larger than the housing bore IIRC. If I had a slightly worn housing but the surface still looked OK, I'd get one of these and stuff it in there....just get one for an undersized impeller...install the wear ring into the suction housing, measure it, then machine the impeller pilot to .025" less than the ID of the installed wear ring. This should set you up good.
Here's the thread where I built my pump, after my "professionally rebuilt" unit spun the wear ring after the first weekend. Some of the pictures are gone, but you get the idea. I think the most important part is making the impeller fit the shaft properly and machining the impeller on the shaft to get runout as low as humanly possibly.
http://www.socaljetboats.com/jet-pumps/blowed-up-pump-autopsy-and-the-rebuild/msg118668/#msg118668 (http://www.socaljetboats.com/jet-pumps/blowed-up-pump-autopsy-and-the-rebuild/msg118668/#msg118668)
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Here are some pictures of my bowl vanes and worn bushings.
Do you think the leading edges of the bowl can be cleaned up to use this same bowl? I have seen other bowls that the leading edges of the vanes are more straight. Are the leading edges supposed to have this shape that mine has? I also measured the gap between the wear ring and the suction housing at 5/32 of an inch. I dont have an isolater to see if it will be tight enough to use the suction housing. Will a ultimate wear ring take up this much space?
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Bowl looks a bit beat, I'm more concerned with offset looking wear of the bowl bushings than the vanes...vanes can be cleaned up to work...not optimal, but OK. Is this a grease or oil lubed bowl?
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Here are some pictures of my bowl vanes and worn bushings.
Do you think the leading edges of the bowl can be cleaned up to use this same bowl? I have seen other bowls that the leading edges of the vanes are more straight. Are the leading edges supposed to have this shape that mine has? I also measured the gap between the wear ring and the suction housing at 5/32 of an inch. I dont have an isolater to see if it will be tight enough to use the suction housing. Will a ultimate wear ring take up this much space?
Those dings in the leading edges of the vanes of your bowl are pretty minor and can be detailed out without much drama. That looks like a Dominator bowl and is a very good bowl design and is worth saving. Are the bushings worn egg-shaped or is it the bore in the bowl that is damaged? Most likely, a repair sleeve can be pressed in to repair the bore in the bowl.
I can’t tell from your pics, but is the wear ring bore in your suction housing all chewed up from spinning the wear ring?
If the wear ring bore is not chewed up, but is on the large side of the tolerance, stainless steel shim stock can be used between the insulator and housing to bring the press back to nominal. You can always pin the wear ring to prevent that from happening in the future. If you simply just pin the wear ring without sufficient press, the insulator can extrude forward from bowl pressure acting on it and this will happen again.
Spinning the wear ring out could also have been caused by debris wedged between the impeller and wear ring. Operator technique could prevent all of this damage. A couple suggestions: 1.) Don’t run the boat on the trailer without disconnecting the drive line. 2.) When launching, dunk the jet pump, pull forward, and then launch the boat. This flushes any road debris that has accumulated in the pump during trailering. 3.) Don’t drive the boat off of the trailer. Walk the boat out to thigh-deep water and bounce the pump up and down a few times to further flush and debris before starting the engine. 4.) Do not drive up on the beach or drive off the beach while beaching. The jet will suck up all sorts of debris from the bottom including rocks and sand that will damage the pump. 5.) A little periodical inspection and preventive maintenance will help your pump live a long and happy life.
Cheers,
Joe
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There's a nice bowl for sale over on PB for 250.00 Been detailed by Chris @ B1. If your not comfortable with what you have that would be a great option.
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Patch, If you want to drive down for the day, I'll go through your pump for $100 plus parts. I have a big mill and big lathe, we'll make it right. Need to fixture up everything and see what we've got to work with...then take it from there. I've got a new Koyo thrust bearing in stock, as well as bowl bushings and other misc. parts. You're welcome to hang out and watch/help/learn
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Patch, If you want to drive down for the day, I'll go through your pump for $100 plus parts. I have a big mill and big lathe, we'll make it right. Need to fixture up everything and see what we've got to work with...then take it from there. I've got a new Koyo thrust bearing in stock, as well as bowl bushings and other misc. parts. You're welcome to hang out and watch/help/learn
Badass!!! I love this site for reasons like that!
Sent with my Fingers
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There's a nice bowl for sale over on PB for 250.00 Been detailed by Chris @ B1.
That is a killer deal on that bowl. The detailing alone cost that. That is a modern Berkeley G bowl off of Windwalker. I don’t believe that there is anything wrong with it, he is upgrading to a Dominator bowl.
If your impeller has the second wear ring on the bowl side, that Berkeley bowl will need to be machined to accept it or your impeller will need to be machined to work with the stuffer plate. Also, your Dominator bowl is about two inches longer, so adjustments will need to be made to your steering.
If you can bring your Dominator bowl back online, you will have approximately the same performance as the fully detailed Berkeley bowl. If you do a full detail to your Dominator bowl, you will have even better performance. I think you will be impressed with your performance after you get all the dings in your bowl and impeller cleaned up and your pump properly clearanced.
Cheers,
Joe
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The berk bowl has a smaller OD than the Dominator bowl, so he'd need a new Transom adapter too.
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The bowl bushings are what is egged out. It oesnt appear to have gotten into the bowl bore. It is a greasable bowl through the rear plug. I would like to take you up on your offer. can you PM me so we can exchange contact info and what parts I will need to purchase? Thanks for everyones help and support! This is what makes our sport great. Great people helping people. After I dissassembled my pump I thought I was going to miss out on a lot of boating this summer. I feel much better it was quite as bad as I thought.
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Do you think it would worth adding a inducer since everything is apart? Would I notice any benefit?
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PM sent
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Do you think it would worth adding a inducer since everything is apart? Would I notice any benefit?
Absolutely! Now is the time to do it while you have it all apart. The shaft is the last thing to come out and first to go in. If you wait, you have to repeat all this work plus machining for the inducer.
You will see a noticeably more aggressive launch and a few MPH gain on the top end.
Sent from my DROID RAZR using SoCal JetBoats mobile app
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After a closer inspection the shaft did get into the bowl. I decided to take the pump to GS Marine. Greg had to send the bowl back to AT to be repaired and powdercoated. I hope to have everything back next week. Thanks for everyones offer to help.