Which Brand HO Pump?

[handcannon]

Due to some overheating when towing I'm checking out different brands of HO water pumps. This is for the 94 in my sig line. The radiator is a used one I found to replace the damaged stock rad that was on the truck when I got it. No overheating problems except when towing my TT up hills.

The rad is all brass, non aluminum core. I took the rad down to the local rad shop and had them go through it so it's clean inside and out. The AC condensor is new so it's clean. The oil and tranny coolers are clean. The thermo crossover was broken when I got the truck so I found a used dual thermo crossover. I have already changed out the fan and clutch to a DMax fan and 97 severe duty fan clutch. The only thing not changed is the water pump, it's still a stock 94 pump.

Rockauto shows a long list of pumps with widely varying prices. I've read that the 99 pumps were better output than the earlier ones so that is the year I will list. Many of these pumps were the same part number for 1997 through 1999. I'm not even considering reman pumps. My question is what brand have you used and how well has it held up? I will list the ones I'm considering.

Bosch #99153 $59.79

Airtex #AW5074 $63.99 (never heard of this brand before)

Gates #44042 $66.79

Cardone Select #5511130 $66.79

AC Delco #252717 $83.89

Rock Products #WP3195A $94.79

There were other new ones listed that were even cheaper but I'm leary of them. Maybe it's the guality of the bearings or other parts used?

Any info/firsthand experience you can give me will be appreciated.

Don

 

[buddy]

Are you overheating with the setup you have now, with DMax fan? What temps are you getting to and do you hear the fan engage? What were you towing?

You might not have a water pump problem, but a fan clutch engagement problem.

In any case, if I was going to go to the trouble of changing the water pump I would pick the stock pump for the year 2000 trucks with spin on fan clutch, AC Delco or whatever. I realize you already have the new bolt on clutch, but the 97-99 "high output" apparantly had an imbalance issue between heads. Might be better off sticking with what you have and just do fan clutch mod.

 

[handcannon]

Looks like I missed some important info. Sorry!

The overheating was with the current setup. The temp hit between 215/220*. The fan did NOT come on. The TT is just over 9K lbs.

I have towed a couple times locally where the highways are flat with no heat problems. The heat problem was going over the Coast Range hills. There are three or four moderate climbs, 1-3 miles long. Once I topped the hill the temps immediately went down.

At the campground I removed the fan/clutch and tried to do the mod. The spring was so short that I could only increase the length by 1/8th". This left only 1/8th" of the spring holding in the clutch body. On the way home the fan still did not come on and temps still went up, even though I was real careful with speed/engine RPM.

When we got home I took the spring off the old clutch, increased the lenght by close to 3/8ths" and installed it in place of the origional spring on the new clutch. I haven't towed the TT with this mod yet. I will be though this weekend for church family camp. This road has some climbing, but not like the road to the coast. It is also narrow and crooked where most of the climbing is so it won't give quite the same test as the road to the coast.

If the current mod with the old clutch spring on the new clutch doesn't do the job I'm going to try to make an extension for the new clutch spring and re-install it on the new clutch.

Do you have any links to info on the imbalance problem with the early HO pumps?

Right now i'm trying to get all my ducks in a row. There are so many brands of WPs out there that I am wanting to know if there are any brands to avoid.

Thanks for your input.

Don

 

[matuva]

I've been using the ACDelco and Airtex ones with no problems.
On my Zuki, I have a BenckArtley one, very nice one, GMB is also a good supplier of waterpump.

I don't know much about the other ones, though Cardone select is probably a reman one (check the ACDelco is the brand new one too).
I never tried the cardone waterpump, but had issue with power steering reman from ACDelco and Cardone....

my .02

 

[buddy]

Then it sounds like the severe duty clutch is not a desireable one.

There was a Heath Article in MaxxTorque a year ago or so that explained why his kit was beneficial and testing they did about the imbalance. There is also a thread here somewhere about the Heath Aritcle. Basically said only high flow pump he uses is the 2000 year, which started sometime mid 1999 maybe, which is what you might have heard about 1999 pumps. The distinctive part of them is they have spin on clutch rather than bolt on, so you'll know it when you find it.

 

[bk95td]

I've got the bosch ho pumps for 97s on 3 of my trucks. No problems yet.
Heath modifys the gm pumps to restrict the bypass going back to the pump from the thermostat housing. That mod forces more coolant to go to the radiator instead of back in the engine.
The housing is slightly different on the 2000 pumps.There is supposed to be less cavitation from previous models.

 

[handcannon]

Then it sounds like the severe duty clutch is not a desireable one.

There was a Heath Article in MaxxTorque a year ago or so that explained why his kit was beneficial and testing they did about the imbalance. There is also a thread here somewhere about the Heath Aritcle. Basically said only high flow pump he uses is the 2000 year, which started sometime mid 1999 maybe, which is what you might have heard about 1999 pumps. The distinctive part of them is they have spin on clutch rather than bolt on, so you'll know it when you find it.

When it comes to the severe duty clutch---I AGREE!! However, I am on a very limited income so I have to try to make it work at least for a while. I have no money for replacing it very soon. If I can make it work for a while without going to a HO pump then my chances for replacing both at an earlier date get better.

I'll search for the MaxxTorque article.

Thanks for the info.

Don

 

[handcannon]

By the way, here's a pic of what the severe duty clutch looked like. The pic is of a Hayden brand and the one I got was a NAPA TEM 271339. You can see why the spring was not long enough for the mod.

Seems like I have a proclivity for learning things the hard way. Now I know to watch for the spring attachment method. That's why I'm posting this pic, so others will know about this type of clutch and what to watch for.

Don

 

[handcannon]

matuva

Thanks for the heads up on the AC Delco and Cardone reman steering parts. I've been hearing recently of too many problems with reman parts which is why I did not include reman pumps in my list. The Cardone pump I listed from Rockauto was listed as new. The AC Delco unit did not say one way or the other. Rockauto did have two Cardone reman pumps listed, which I am not even considering.

Barry

Good to hear about the Bosch HO pumps. If the mods I'm trying now don't work I'll probably go that route since they are cheaper.

I just recently found out that Heath reccommends the single stat crossover instead of the dual stat. Of course I found this out after I found a dual stat crossover to replace my broken single stat crossover. In my sinlgle stat crossover the stat as it opened pushed a plate down to block the flow through the bypass, forcing the all the coolant through the rad. Maybe this is why Heath says the single stat is better than the dual since the dual stat crossover bypass is always open. Maybe I can come up with a way to restrict the bypass to force more coolant through the rad.

Don

 

[bk95td]

A while back someone posted pics of a restrictor they made. They threaded the inside of the hose nipple and put a reducer bushing/drilled out plug in.

 

[buddy]

The nipple that comes off the water pump, which has a hose that goes into the T-stat housing.

I believe in this case though youll be fine if you just get that clutch to engage, it really will do fine after that.

 

[Acesneights1]

The Haydn SD clutch has more lockup and works better than stock./ I am running it with a stock 9 blade steel. You problems overheating are typical of a 6.5TD. I have had 3 of them and they all did the same thing no matter what you use or did. Yes the mods help and cleaning helps alot but the MOST important thing is to realize it's not a Cummins or a Dmax. You can't hammer the thing going up hills. You NEED EGT, and Boost guages and you have to clsely monitor your temps and how much fuel and boost you are pushin into it. If your egts are climbin through the roof back out of it. Remember aluminum melts around 1200 degs. May want to cut the boost back a little too. Remember to push 10+lbs of boost you are slammin the wastegate shut and all that heat (EGT's) is trapped in the motor. Cut the boost back a little even if it means loss of power. Bottom line, when you mod these trucks you take the saftey blanket of the ecm out of the loop and now you must think for the truck. My 2000(which already has the good cooling system) ran nice and cold with no real issues towing a TT etc but I recently put a TM on it because the vac Pump was shot and Bill Heath reflashed the ecm and now the egts literally climb as fast as i can push the accel pedal up a hill with a trailer on the back so next time you tow try watching your guages. You see egts starting to climb, back off.

 

[Acesneights1]

If you want my honest opinion, Robyn(MGW) was on the right track with using a modded Horton lect controlled fan clutch. That is what these trucks really need. These viscous fluid clutches suck. They are all over the place. I have an old 2000 WP and and Old WP from a Superduty PS waiting to experiment on when I have time.

 

[buddy]

Any tow vehicle needs the fan to kick in under load, you cant blame the powerplant for overheating if the fan doesnt kick in. Blame the people that decided what temp it should kick in, which isnt where you want it to. These engines can do a lot when all the cooling system is working

 

[Acesneights1]

My fan kicks in fine and it still runs hotter than a PS or Cummins towing the exact same load. Not saying a 6.5 can't do it, but you gotta use your head driving it. If you put a tune and a Mech WG and then throw a trailer behind it and mash it to the floor going up a steep grade , it's not going to be happy. I've towed the EXCAT same camper with a PS, a Cummins and my 3 6.5TDs pre and post mods and the 6.5 Post mods runs the hottest. substantially more so.

 

[buddy]

Must be the way it was tuned, sustained advanced timing can cause problems. For towing I dip the timing if sitting at about 3/4 fueling capability, but jump it way back up at the high end of fueling capability. And I very much recommend if anyone is towing in heat, then get rid of the anti-freeze, run only 10% antifreeze with a bottle of water wetter or hyper lube, it will stay much cooler.

 

[handcannon]

Acesneights1-- good question about the gauges, didn't think about that info earlier. I was watching my EGT and water temp. The EGTs never went above 1100, mostly around 1050. When the water temps started climbing I started slowing down. I was so concerned about the water temp that I forgot to keep watch on the boost. In previous attempts while messing around trying to get the boost to go high I never could get it to go over about 13-14 lbs.

I'm inclined to side with Buddy, get the fan to cut in and the temps will be under control. That's the way I'm going anyway. I just want the WP info in case the trip this weekend shows me that my latest mod won't work.

Don

Don

 

[buddy]

Make sure you arent putting in too much antifreeze, the less the better.

 

[Acesneights1]

those egts are fine. I was easily hitting 1300+ if I kept my foot in it. I am seriously considering fixing the vac pump and putting the stock tune back in. Truck was much better stock. Less power but ran much cooler.

 

[WarWagon]

I've got the bosch ho pumps for 97s on 3 of my trucks. No problems yet.
Heath modifys the gm pumps to restrict the bypass going back to the pump from the thermostat housing. That mod forces more coolant to go to the radiator instead of back in the engine.
The housing is slightly different on the 2000 pumps.There is supposed to be less cavitation from previous models.

2000 housing will also balance the flow to both banks better. MaxTorque article on 1995 Heath burb claims so.