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Topic: Hydraulic pump (Read 860 times) previous topic - next topic

Hydraulic pump

I have a late 97 U295 3600 WTFE w/55.000 miles.  I purchased it this past feb. and at the time it had 51,00 miles.  I had help checking it before purchase and all systems and accessories were in good condition.

After driving it approx.2500 miles upon leaving the GLASS rally in MI. I heard a squealing noise from the Hyd. pump and discovered the belt was beginning to come apart.  The belt was replaced and I drove another 1200 miles home and rechecked the new belt.  It appears to be wearing prematurely.  I am still hearing the noise but it seems to go away after about 10 mins. running.  Gary Omel seems to feel that belt pulley turns unusually hard by hand and that the pump is failing.  I have checked pulley alignment and wire brushed the pulleys to remove any rust/contaminants.  Foretravel has identified the pump as a Sauer-sunstran model 41188.  I would like to know if anyone has had a similar experience and if the pump can be rebuilt and where in the Florida area. 

Foretravel has quoted a price of $ 1,550 for a new one.

Fred Wolff    Motorcade # 16961

Fred, Dawn and Bandit
1998 U295, 36', build # 5233, Motorcade # 16961
2007 Black Saturn Vue

Re: Hydraulic pump

Reply #1 –
Fred,

The belt on our 1997 U295 was noisy soon after it was replaced at MOT immediately after we bought our coach. I thought the problem was bad bearings in the idler, so I replaced that. There was no improvement. In January, 2011, I asked the folk at FOT to check the noise problem. They reported that the belt was not the proper size and replaced it. It hasn't squeaked since.

I suspect your problem is not an improper belt, but it is worth considering. The belt on my coach is NAPA 25-080465. The belt is relatively cheap and very easy to replace. It's good to have a spare anyway.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Hydraulic pump

Reply #2 –
The original and replacement belt are the same as yours and is the one specified in the manual.  Others I have had review the problem have shown concern for the way the belt rides in the grooves. Thanks for the input.

Additional input:  I cleaned the pulley and under the pulley (wear dust) before going on a 200 mile test run and there was near no new dust on return.  The pump shows no sign of leakage nor bearing, end shaft, over heating.

I find it surprising that with all the information supplied with the coach there is little/no information, I found, about the pump.
Fred, Dawn and Bandit
1998 U295, 36', build # 5233, Motorcade # 16961
2007 Black Saturn Vue

Re: Hydraulic pump

Reply #3 –
Fred, IF you have to pull the pump, any competent hydraulic shop should be able to rebuild it.
Call this guy for info.  Grady Coggins, 770-860-1001, He owns a hydraulic repair shop here in Conyers.
Good Luck
Gary B

Re: Hydraulic pump

Reply #4 –
Thanks for the info Gary.  I called and although the shop is closed he was very encouraging about the likelihood of it being rebuild/repairable.  I will post results of conversation tomorrow.

I think we met at Gary's house this past year.
Fred, Dawn and Bandit
1998 U295, 36', build # 5233, Motorcade # 16961
2007 Black Saturn Vue

Re: Hydraulic pump

Reply #5 –
Before you get into the pump, use a 3/8" ratchet or breaker bar, release tension on the idler pulley (wheel) with one hand and with the other hand, spin it. It should spin easily. The belt should go from one side to the other with no groves visible on the crank pulley or you could have the wrong belt on. You should be able to check this in less than a minute if you have a side radiator setup. My U300 has a belt 8 grooves wide.

What kind of wear are you getting on the belt? 
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Hydraulic pump

Reply #6 –
Fred, I watched you strip decals last winter at MOS, then we met later at Perry.  You ended up with a great machine.
Gary B

Re: Hydraulic pump

Reply #7 –
Quote from: Pierce & Gaylie Stewart –
Before you get into the pump, use a 3/8" ratchet or breaker bar, release tension on the idler pulley (wheel) with one hand and with the other hand, spin it. ...

Cummins brand idler uses 1/2" ratchet or breaker bar. I think Dayco and Gates use 3/8".
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Hydraulic pump

Reply #8 –
Couple things:  My idler uses a 3/8" ratchet/breaker bar.  The idler itself spins quite freely with no bearing noise or vibration "seems" to be O.K.
Gary Boulan: I have contacted Grady Coggins and have sent him pictures of the pump in hopes of identification.  I will keep you informed on how it goes.  I believe based on discussion with him of the sound it makes and that it seems to diminish over time, it may be fluid deprived.  I have not had time to investigate a hyd.fluid filter issue but I am going to look at that possibility.
Fred, Dawn and Bandit
1998 U295, 36', build # 5233, Motorcade # 16961
2007 Black Saturn Vue

Re: Hydraulic pump

Reply #9 –
Latest info:  Grady's response to the picture "That looks like a PRINCE or CROSS gear pump, they are sold all over the world under different names so you should be able to have it checked out at any local Hydraulic shop. You should first have the hydraulic tank cleaned out and install a new suction hose, then if you are still having the same problem take the pump off and have it tested."

I will follow his advice and keep this post "alive" until corrected.

Thank you all for your help!!!

Fred
Fred, Dawn and Bandit
1998 U295, 36', build # 5233, Motorcade # 16961
2007 Black Saturn Vue

Re: Hydraulic pump

Reply #10 –
Fred,

Cavitation can sound very much like a mechanical problem. The fact that it goes away after a few minutes may indicate that as the fluid warms, it becomes less viscous and enough fluid is supplied to the pump so the noise goes away.

Question: once the engine is warm and the noise is gone, does it reoccur during that day or only after the engine and fluid have cooled?

BMW power steering pumps were famous for this. There was an almost 90 degree turn from the pump up to the reservoir and as the supply hose aged, it partially collapsed at the turn causing nasty cavitation noise. I changed filter but had no luck until I went to a forum and discovered many others with the same problem and found the solution. The turn in the hose was hidden and hard to check the condition.

So, in the case of cavitation, a hose could be restricted making a turn or have interior degradation. A clogged filter is another possibility. Check for foam in the return line if you can see into the tank.

Here is a link to a description and damage it can cause: http://en.wikipedia.org/wiki/Cavitation
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)