• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Coolant Leak , Front of Engine

Foehammer

Foehammer

Member
Messages
60
Reaction score
0
Hey again guys, Ok here's my problem: My truck has developed a coolant leak that from the bottomm of the truck is dripping from between the harmonic balancer and the oil pan, could it be my water pump, or water pump gasket or the backing plate gasket, or could it be something else?

My truck is a '94, and I have to remove every frickin thing from the front of the engine in order to replace the water pump, and gaskets, so should I replace the harmonic balancer, and secondary balancer(pulley) as well, while I am at it?

I am going to be upgrading to a HO pump, and Heavy Duty fan/ Clutch combo, if I have to do all this as well, but do not want to fork over $600+ for the heath kit. SS diesel has HO pumps and fan upgrades for less than $400 combined, for both 94-99.5 yr, and 99.5+(with the screw on fan and pressed on pulleys), will the 99.5+ yr pump fit on my '94, or would I have to replace the backing plate?

Does anyone have any experience with the SS diesel pumps/fan clutchs, and can speak to their quality?

Or does anyone know what parts/ part #'s I should order from Rock Auto to do this job?

Do I need to use a double T-stat setup or should I stick with the single T-stat?

I have removed all my vac components witht the exception of the vac pump and will be leaving that off and getting a vac delete belt, any suggestions for that belt that are cheaper than the one Heath sells?

I have replaced the plugs and injectors, done the upper plenum gut, and clean before, so would this be something that I could reasonably handle, and what kind of time should I set aside for this job?
 
I would say its coming from your water Pump From your description, Dont wait too long before you fix it because its the bearing failing that is causing the seal to leak, as far as the belt on my 98 I needed a 99 1/2 inch 6 rib serp belt when I take off the vac pump, any auto parts store will have it, But yours is routed different so Im not sure of the length
 
X2^^^^^^^

Water pump is the culprit most likely.. I have a 95 and use a k10106 belt with the vac delete,if that helps.

I just replaced my pump last week with a 98 HO pump from rock auto. The bottom weep hole was leaking coolant on my balancer also, and the bearing was shot. The impellar is 5/16" bigger on the HO than our standard pump and the passages are also measurably larger. It only takes about an hour or so to change so don't procrastinate and get it done before the bearing locks up. BTW. I got my pump for 72.00 delivered to my door for a new lifetime warranty gates pump,that said delco on it and powder coated black. pt# 44042, and dmax fan,#1580690, and clutch #2831 but you can get it cheaper at advanc or AZ.

Merry Christmas
 
Before going after water pump another source that is deceptive is the heater quick disconnect on outlet of the T stat housing, it's pot metal and corrodes over time and also has "o-rings" in it to seal that become "square rings " over time and leak & weep down the side of the block looking very similar to the weepage that comes out the water pump "tell-tale" weep hole.

Could be the WP but check the heater supply fitting as well.
 
Last edited:
:rof:
better read my poem if it's that...
Advance gets about 200$ for the HO 2000 WP which is the best one. It will require a spin on clutch which the Hayden severe Duty was 150$ from NAPA.
 
Turbine Doc said:
Before going after water pump another source that is deceptive is the heater quick disconnect on outlet of the T stat housing, it's pot metal and corrodes over time and also has "o-rings" in it to seal that become "square rings " over time and leak & weep down the side of the block looking very similar to the weepage that comes out the water pump "tell-tale" weep hole.

Could be the WP but check the heater supply fitting as well.
Click to expand...

Good point I never thought of that
 
Here are some pics of what I'm talking about, many replace with a common barb fitting, there is an aftermarket replacement steel fitting if you want to maintain the quick disconnect, some folks say the orifice in the OEM fitting is a requirement, both of my 6.5s have been "barbed" to no ill effect for years.

On the aluminum heater hose side I used tubing cutter to remove the qd end and double hose clamped for sealing, it's 1/2" NPT to 5/8" barb fitting, it's 50/50 shot the GM q'd fitting will come out intact, some break off some don't so you'll want thread restore tools handy, when you remove old fitting. crossover will have to come off possibly so you can work the threads.

Balance flow 10.JPGBalance flow 11.JPGBalance flow 8.JPGBalance flow 7.JPGBalance flow 27.JPGBalance flow 9.JPG
 
Turbine Doc said:
Before going after water pump another source that is deceptive is the heater quick disconnect on outlet of the T stat housing, it's pot metal and corrodes over time and also has "o-rings" in it to seal that become "square rings " over time and leak & weep down the side of the block looking very similar to the weepage that comes out the water pump "tell-tale" weep hole.

Could be the WP but check the heater supply fitting as well.
Click to expand...

Would this only leak after the engine was warm enough to open the T-stat?

Ok I just saw your pics with the barb fitting , Thank you very nmuch for the info, will try to let my engine warm up, to see if this is the culprit, will let you know asap.
 
Last edited:
Ok, I let the engine heat up and the leak showed on the ground, but when I popped the hood, and inspected the quick disconnect, no leak there :( ,so I guess I am back to having to replace the water pump, I have been trying to get an inspection mirror down on the bottom side of the pump to see if the weep hole is actually leaking or if it is a gasket, but I cant see anything down there. The only places that could cause the leak I am describing, are quick disconnsect on crossover, water pump weep hole, wp gasket or backing plate gasket, correct?
 
Yes, I agree with TD. Check that quick connect on top. It is way up there and coolant can go anywhere before assuming the worst.

It is an easy fix and more prone to leaking. It shows up during winter because the coolant does not evaporate as fast.

I replaced mine last winter for good.
 
It's the water pump, and to rule all else out remove the belt and spin the pump and if you hear a grinding noise or if you pull on it and see/feel shaft play you know for sure.

The by-pass usually leaks down the side of the block as coolant will travel to the lowest point on the under side of hose before dripping off.

You say the coolant is dripping on the balancer,It's the pump and I gave you the part #s and it's not the spin on clutch type. it's for our trucks. 94-95 Go on rockauto.com and look it up as a 98 and look at the pic. Get the gates pump 72.00 to your door in three days /lifetime warranty and it's new not reman. I will stake my life on it just get the pump and be done with it. Ijust went through all this last week, good luck and post what is the problem after you confirm it so as to help others in the future who read the threads.
 
Only problem there is, you need the sheckles to upgrade to the 2000 spin on WP, need new spin on fan clutch, and might as well get a D Max blade.....Difference betweeen $100 WP and a $3-$400 upgrade.
 
If I am going to do this I will upgrade the fan at the same time so, I think I will go with the 2000 HO WP (providing it definately fits the '94, I don't wanna have to return an order). I found all of these thru Amazon for less than $250 w/ free shipping, bosch 99159 HO wp $76.39, acdelco 1580690 fan blade $55.38, acdelco 154691 fan clutch $114.80. I will also be ordering a Vac pump delete belt and backing plate gasket from Rock Auto. I want to have the best balance with my cooling, I as yet do not tow with my truck, but live in Southern New Mexico so every bit helps. Should I replace my Harmonic balancer while I have everything off the front of the engine, or is that something I can do later with ease? Is there anything else I should do while I have everything off the front of the engine? My big problem right now is that I will have to have my truck off the road until after the 15th of Jan when I get more spendin money (Christmas hit the wallet hard this year, rent due in a week).
 
You want a "Severe Duty fan clutch".....Not OEM Delco, they run about a $150.....They engauge a little earlier and spin a little faster then "Heavy Duty" or "OEM"
 
You must log in or register to reply here.
Back
Top