Blew up ANOTHER PS pump

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Blew up ANOTHER PS pump

August 27, 2007, 04:08:58 PM

I am getting tired of this. At least this time it didn't happen at the starting line at the racetrack :( I've been meaning to give my underhood a nice oiled polish though

Ok, so I bought an AGR "performance" pump and it blew the front seal out at the track (how does a seal get ejected out onto the shaft anyway??). I got an OEM replacement and it lasted a couple of years - woohoo

This time it blew when doing a 4th gear WOT blast. They always blow when I let off after a WOT blast. I think it may be that I have the blower on there putting a heavy load on the pump bearing combined with the fact that I had the belt tensioner too loose both times - and it kicks back wicked bad when the tension is let off the S/C. I think the tensioner actually binds for a split-second as it goes past the point of no return toward the alternator - but I'm not sure why this would kill just the PS pump. I checked the pulley alignment - it is within 10 thousandths of an inch best I can tell by eye, so that doesn't seem to be it.

Any ideas on this would be appreciated.

I was going to give up and get a manual rack, but I can replace the pump and rack for ~ $120, perhaps starting with an all new system will help. I did flush the system and deair it last time, but who knows - the rack is 20 years old.

Blew up ANOTHER PS pump

Reply #1 – August 27, 2007, 04:14:01 PM

Could be a fluid restriction in the rack itself.
I'd say give it one last try and replace both the rack and the pump.

Blew up ANOTHER PS pump

Reply #2 – August 27, 2007, 06:07:41 PM

Yep, going to go nab a new pump & rack now...

Blew up ANOTHER PS pump

Reply #3 – August 27, 2007, 06:54:44 PM

maybe put a bigger pulley on the Pump.. I can't quite remember what car it is.. but either a 3.8 or some big bodied car has a one inch larger pulley..

Blew up ANOTHER PS pump

Reply #4 – August 27, 2007, 06:56:11 PM

I have to offer, I got the pump and all the lines from my car if ya need

Blew up ANOTHER PS pump

Reply #5 – August 27, 2007, 07:04:41 PM

just really quick, how good do you think a v-belt set up works on a sepitine 5.0 car?

Blew up ANOTHER PS pump

Reply #6 – August 27, 2007, 08:58:56 PM

Almost all 3.8s have the big pulleys.

Blew up ANOTHER PS pump

Reply #7 – August 27, 2007, 09:03:26 PM

I'm not sure if it would help in your situation Cougar5.0 but slowing the pump down may help. What RPM are you turning your engine too? I'm guessing you are nearing the 7k RPM mark? Probably way too much for the stock pump.

Blew up ANOTHER PS pump

Reply #8 – August 27, 2007, 09:21:02 PM

I only spin the engine to 6k. I have a brick-wall rev-limiter & timing pull that prevent me from going beyond 6100 RPM.

The thing about this time is I didn't even get over 5k RPM. The big difference is I put on a new idler pulley for the blower and I wasn't able to find a belt quite small enough. Since my engine came with a 6.5" crank pulley and I now have a 5.85" crank pulley from a Mustang, I'm really not spinning this thing that hard.

I did go out and nab a new pump, high-pressure line and rack. For $137 (all LLT warranty too) , it's really not much of a gamble. If you count the new control arms & 11" brakes I'm putting on, I'm looking at an entirely new front end - lol. Thanks for the offer Fila, I'm all set now.

I may look into finding a 3.8 pulley at the junk yard since I'm gonna need to rent a pulley puller tool anyway. I hardly ever see any Fox bodies at the junk yard any more though, so it could be a challenge. Anybody got one lying around? lol

Hey Jeremy - I'm dissapointed in you - you usually come up with a much more snarky remark - lmao!

Blew up ANOTHER PS pump

Reply #9 – August 27, 2007, 09:56:41 PM

I think the MN12's have the same big pulley.

Blew up ANOTHER PS pump

Reply #10 – August 27, 2007, 10:02:35 PM

Yeah? Cool. I want that pulley since I may go back to the 6.5" crank to minimize belt slip and maximize boost :D

Blew up ANOTHER PS pump

Reply #11 – August 28, 2007, 12:00:53 AM

The larger 3.8L pulleys are normally used to keep the PS pumps from dying a premature death on cars that see autocross or road courses. The bypass on the pumps can be overwhelmed at high rpms, resulting in the pump giving your engine bay the bukkake (somehow this word isn't in FF's dictionary) treatment.

I'm not certain, but I think your problem might be related to the belt tension. Is this common with other SC setups like yours?

If the SC run off the same pulley as the rest of the accessories?

Blew up ANOTHER PS pump

Reply #12 – August 28, 2007, 12:16:57 AM

Yeah, the same belt runs the blower. The PS pump is before the blower in the power path, so I think it is getting abused as my S/C alternately draws 40 HP, then releases when I let off.

I don't know what bukkake means, but I'm still finding little ****ing crevaces in the water pump/brackets with fluid on them. This pump not only blew all the fluid out onto my engine bay, but it then proceded to lock up solid and can NOT be rotated.

I really do think that when I have the tensioner adjusted too loosly, it allows the wild belt backlash that I was trying to describe before. I think it's no coincidence that I had just the day before changed the belt to one that was letting the tensioner unwind all the way during throttle jukes.

Blew up ANOTHER PS pump

Reply #13 – August 28, 2007, 07:39:43 AM

Put a 3.8 in the car and then you won't have these problems.LOL.

Blew up ANOTHER PS pump

Reply #14 – August 28, 2007, 09:03:33 AM

Quote from: vinnietbird;172639

Put a 3.8 in the car and then you won't have these problems.LOL.

Yeah, that's what I was thinking - lol. Actually, there was an interesting article in 5.0 or MM&FF about this hot chick who also built her V6 for drag racing. She did N/A, then supercharged, now she's going with twin-turbos! The car was getting pretty fast!