Pretty slow around here lately. Time for some Tech Talk! Besides I haven't sparred with PB lately, feeling lucky...

Last fall one of the heater hoses under coach blew out. I bypassed the cab heat loop, refilled, and continued without engine cab heat. I planned to replace the hoses but considering the engine hoses are all 1995 OEM, I decided it made more sense to replace engine cooling hoses first, then worry about the forward cab heat lines.

Since the old parts were so dirty, it was harder to get good photos. Instead, I took photos as I reassembled and reversed the order.

Some old bloated hoses:



Here we go:



The outlet elbow is at the top rear. I removed the elbow and the air bleed lines. Removed the belt and the alternator bolts.



Since the cooling pipes were rusty I removed them for cleaning and painting.



The outlet pipe is attached to the thermostat housing with two bolts. Two more and the housing comes off. I left the belt tensioner and the alt mount attached.



Below the housing are the 2 thermostats:



Now for the fun part. Behind and below the thermostat housing are the water inlet elbow and 2 heater hose connections.



A real PITA to get that elbow in there... this turned out to be the worst part of the job. I "greased" the hose end and stump with RTV sealer (very slick) and forced it on with fingers and a metal "shoehorn."



The lower pipe has a tap for the 1" filler hose from the reservoir.



Rather than straight to the rad it forms a loop forward through the power steering cooler, then back to the radiator. There is also a short 5/8" hose that comes from the block.



Found a good replacement for the upper elbow. Enough extra for the coupler hose below.



Engine parts you will need:

-Inlet elbow: Cummins 3920762
-Outlet gasket: Cummins 3918779
-2 thermostats: Cummins 3928639
-Thermostat housing gasket: Cummins 3914310

The rest are hoses and couplers.

-1 outlet elbow hose 2 1/4"
I used a Dayco 70921 hose. (Trim to fit, the extra can be used for the 2 1/4" coupler below)

-2 reducers: 2 1/2" x 2 1/4"
One for the front end of the cooler, one for the front upper radiator pipe

-1 straight coupler 2 1/4"
rear end of cooler to engine pipe

-1 straight coupler 2 1/2"
rear lower radiator pipe

-5/8" heater hose for the heater loop forward and the bypass on the engine block.

-1" heater hose (6 ft) for the filler line.

It took about 9 gallons of coolant to fill the system. I did not completely drain the block, I suspect a complete fill would be about 10 gallons.

This means I have now replaced every rubber coolant component. I believe most were 1995 vintage. Now I can trust them. I can get back to those darn heater lines without worrying about my friendly Cummins.

excellent photo story with clear images

quote:

Originally posted by Mogan David:
excellent photo story with clear images

Thanks, Mark. (That's why I use a camera to take pictures, not a phone)

Things have been slow here lately. Heck, last week I couldn't even spell deesil mekanik, now I am one!

Thanks Steve you da man!

I imagine that ours should be pretty close to the same. Now I have a personalized play book with part numbers to purchase ahead of even starting the process. You even pointed out the stress creators to make sure to tackle those parts with the right attitude.

Photo bucket played nice with you. Camera instead of phone is a great hint. It is just so handy to use the phone because some of us have it nearly glued to our hands for work.......

I thought you, Deb&Ed and Wally might find it useful, hopefully others. Evidently my posts get some outside attention as well.

Here is a continuation of the Monarch cooling system thread:
Radiator replacement: https://www.barthmobile.com/eve...443958597#9443958597

Have Barth, will travel, soon

Wow over 2 year’s ago?

My parts list seeing I have the radiator out and most of the hoses loose! Might as well do more

Did you local source the hoses or online? Looks like on line without paying expedited shipping (you know I’m to tight for that) some are looking like weeks out.

I hate taking the time to get parts with things torn apart but makes sense to do now. Should have thought ahead but to focused on just one thing. Radiator

quote:

Originally posted by Steve

Engine parts you will need:

-Inlet elbow: Cummins 3920762
-Outlet gasket: Cummins 3918779
-2 thermostats: Cummins 3928639
-Thermostat housing gasket: Cummins 3914310

The rest are hoses and couplers.

-1 outlet elbow hose 2 1/4"
I used a Dayco 70921 hose. (Trim to fit, the extra can be used for the 2 1/4" coupler below)

-2 reducers: 2 1/2" x 2 1/4"
One for the front end of the cooler, one for the front upper radiator pipe

-1 straight coupler 2 1/4"
rear end of cooler to engine pipe

-1 straight coupler 2 1/2"
rear lower radiator pipe

-5/8" heater hose for the heater loop forward and the bypass on the engine block.

-1" heater hose (6 ft) for the filler line.

It took about 9 gallons of coolant to fill the system. I did not completely drain the block, I suspect a complete fill would be about 10 gallons.

This means I have now replaced every rubber coolant component. I believe most were 1995 vintage. Now I can trust them. I can get back to those darn heater lines without worrying about my friendly Cummins.

Update when i took off mine. The number for the elbow actual part number is 21194 Gates hose.

The reducer number is b871729. Dayco hose. This one most couldn’t even find and ship date was 3-4 weeks out.

Advanced had and say 3-4 day ship. We will see.

Nice Job, good to see you working!!