M925 and Broke Water pump Belt

[M35A2-AZ]

I was at benefit display and was on my way home Saturday when the cooling fan came on, I had just looked at the temp. gauge and it was OK. But I looked after the fan came on and it was higher, looked again and it was higher. Time to pull over and check things. As it turned out I had lost the water pump belt, it made no noise at all when it broke.

Got a ride home, got the M923A1 out, (Wrecker is at the AZ state fair on display) got all the towing tools needed and headed back to get the M925, about 30 miles away.
The oil looks OK and the Antifreeze looks OK, so I am hoping it did not get to hot to hurt the motor, it was about 220 degree when I shut it down.

Made it home ok.
So guys keep an eye on the gauges!!

 

[simp5782]

220 is nothing. Mine would see that pulling long hills when I had the allison in it before I would turn my fan clutch on.

As far as water pump belts breaking, do you have the metal impeller pump? Some will partially break and take the belt out but only half the plastic impeller will break. Or just the impeller breaks and they run out.

Not to mention all the cussing about the person that designed the accentric water pump adjustment

 

[M35A2-AZ]

Yes the water pump has the metal impeller. I pulled the water pump to check on it and it was pitted and had holes in it, I will replace it.
You are right about the eccentric design for the adjustment.

 

[74M35A2]

Wouldn't it have been easier to just throw a new belt on it where it was pulled over? I know, not nearly as much fun as dragging out and using all the other cool stuff. Also I don't know anything about the 250 engine, maybe it takes like 1000 tools to change the belt. Doesn't it have 2 belts? I think on the alternator it does?

Good job on watching gauges.

 

[simp5782]

Wouldn't it have been easier to just throw a new belt on it where it was pulled over? I know, not nearly as much fun as dragging out and using all the other cool stuff. Also I don't know anything about the 250 engine, maybe it takes like 1000 tools to change the belt. Doesn't it have 2 belts? I think on the alternator it does?

Good job on watching gauges.

Water Pump has one belt. Fan clutch and mount has to be removed. Upper engine mount bracket for the radiator support has to come off and the mount to the radiator. Upper hoses and cross pipe. You have to remove the power steering belts x 2 and fan belts x 2 to get to the rear belt on the accessory drive.

The fun part is that the waterpump has a copper crush seal on it. You have to take the 6 bolts out of the pump and remove it. Then reinstall it with the belt on it and take a hammer and extension or long chisel and knock the little notches of the water pump counter clockwise to tighten the belt on its eccentric adjustment. Its a stupid way to tighten a belt.

I can do one in about an hour but I know what size everything is and what has to be done with the lots i have done. There are a few shortcuts but tightening the belt is the worst part.


Oh and for those wondering there is an A1 Cardone Water Pump still in production available. Part number 55-91515'

https://www.youtube.com/watch?v=P6Y1P2aVqb0&t=8s

 

[74M35A2]

Yuck. No wonder why he towed it back.

Here is the 8.3L water pump change procedure:
1. Remove the serpentine belt
2. Remove the water pump (three 10mm headed bolts)

 

[M35A2-AZ]

Thanks Simp good write up on it.
I have done two water pump belt and pump changes and it is not to bad if I'm at my shop, but by the road side, getting to old for that. LOL!

For sure it is not like a 8.3.

 

[simp5782]

Thanks Simp good write up on it.
I have done two water pump belt and pump changes and it is not to bad if I'm at my shop, but by the road side, getting to old for that. LOL!

For sure it is not like a 8.3.

biggest pain is putting the fan clutch back on. its heavy and the bracket likes to spin when you want to grab the blades. to lift it back up then trying to hold it up while aligning the mounting bolts. I got tired of it and i bought an extension line to hook to the shutterstat feed line and it hooks to the fan so you put air in your tanks and you let it feed air and lock the fan clutch up which makes it a lot easier to deal with even though it has a hose on it.

or you can feed it air from any air accessory or hose you can rig up to it.

 

[M35A2-AZ]

biggest pain is putting the fan clutch back on. its heavy and the bracket likes to spin when you want to grab the blades. to lift it back up then trying to hold it up while aligning the mounting bolts. I got tired of it and i bought an extension line to hook to the shutterstat feed line and it hooks to the fan so you put air in your tanks and you let it feed air and lock the fan clutch up which makes it a lot easier to deal with even though it has a hose on it.

or you can feed it air from any air accessory or hose you can rig up to it.

That is a good idea!! Thanks

 

[juanprado]

I have the paper gasket for the plate if you go that far and extra copper crush washers.

This is absolutely the stupidest design ever for a water pump and adjustment. I know of no other crazy mouse trap like this one...... I would have love to meet this engineer personally.....

Been There done that, all the best.....

 

[M35A2-AZ]

Thank for the offer, but I have them I my parts stock.

 

[M35A2-AZ]

Got the truck repaired, new water pump and belts. Did a little test drive, sounded ok, oil looks ok.

 

[M35A2-AZ]

I think I am going to add the Engine Hot Light to my trucks but I do not know what Temp. switch to get 210, 215 220 degree.
Any ideas?

 

[Ajax MD]

Wow, how unusual. My understanding is that the M809 series and the 900 series have more or less the same engine. Is the M809 series water pump also this way?

 

[Scrounger]

It takes more time to lower the coolant level and refill than to replace a water pump in an 800 series.

 

[WillWagner]

M35a2, 215 would be a good temp for a light to come on at, the older engines don't like 220 for very long, material from the piston likes to stick to the liner much higher than that.

Ajax, yup, the 809 and 900 series with the 855 use the same design.

It helps with belt adjustments after new pump and belt installation to use LOTS of anti seize on the copper gasket, that will allow the pump to turn easily and help prevent leaks after adjustment is done.

 

[M35A2-AZ]

Will, Thanks I was thinking 215 would be a good one.

 

[CARMAN]

I was at benefit display and was on my way home Saturday when the cooling fan came on, I had just looked at the temp. gauge and it was OK. But I looked after the fan came on and it was higher, looked again and it was higher. Time to pull over and check things. As it turned out I had lost the water pump belt, it made no noise at all when it broke.


Got a ride home, got the M923A1 out, (Wrecker is at the AZ state fair on display) got all the towing tools needed and headed back to get the M925, about 30 miles away.
The oil looks OK and the Antifreeze looks OK, so I am hoping it did not get to hot to hurt the motor, it was about 220 degree when I shut it down.

Made it home ok.
So guys keep an eye on the gauges!!

Totally off topic but does your S280 not fit up in the front of your bed or do you just choose to leave it back?

 

[M35A2-AZ]

Totally off topic but does your S280 not fit up in the front of your bed or do you just choose to leave it back?

Yes it will fit, I just have my inverter and batteries in the front, also put fuel cans and spare parts.

Also the cables fit the bed that way. The cable I had were for a M35A2.