militarydave

Sup Fellas.

Hope everyone had a happy holiday weekend/Black Friday, etc. etc. I'm now having to enjoy the rest of the holiday weekend replacing a plastic heater control valve on my 98 Chevy express G3500 15 Passenger 1 ton van.

I determined that's the culprit as the headgasket does not leak, the radiator, radiator cap, hoses, etc. are all new, replaced and in tact. There is a very small leak coming from the top of the Right (Passenger) Control Arm that consumes coolant at a very slow rate. it also smells like burnt coolant after a short drive.

I noticed a puddle of coolant/water mix under the right wheel, hence below the heater core/heater valve assembly.

I got the part ($15 at oreilly auto parts), I got the chiltons & Hanes, but none tell me how to "GET TO IT"

Meaning: DO I GET TO IT FROM THE BOTTOM OF THE VAN, OR REMOVE EVERYTHING AND ACCESS THE PLASTIC HEATER VALVE FROM THE TOP??

if anyone knows how do access it (i know i have to drain all the coolant) I would greatly appreciate it!

any advice/suggestions/recommendations are greatly appreciated!

miketowncar

same issue here,how did you replace it

lunghd

And another one bites the dust... was hoping to find an easy way to get in there to the damned thing.

lunghd

Alright... another case where you'd strangle / beat-senseless the GM design team on this one but it's done.

Heater valve failed out in the boonies & instantly drained coolant from system. Got lucky & smelled it... checked gauges & had 'oh sh*t!' moment: almost pegged temp gauge. Managed to coast to roadside pullover which (as luck would have it...) had a creek about 100' away. After searching for about 10 minutes looking for source of leak (by adding water & looking for the waterhose sized stream to appear...) I found it.

If your valve goes out - you won't be able to see the damned thing since it is located BEHIND the air conditioner dryer (big silver can in a/c system just next to battery).
You will not likely be fixing this beside the road unless you are carrying an exceptional selection of odd tools. (I would not even try until the engine cools down)
Roadside / broke down: Just bypass the damned thing by looping the rear heater hose (5/8") toward the front and secure it to the other port just forward of the alternator bracket. (You'll need extra clamps for this as the fitting is 1/2" and will leak otherwise.)

My van does NOT have rear heat / ac .
My valve is the 4-port heater control bypass. (there is a 2-port control as well BUT I'm pretty sure this is for the rear heat on vans with that... don't bet the farm, though).
Go ahead and remove the battery when you get ready to replace this valve; you'll need to be able to reach behind the dryer from that side too.


Tools you'll wish you'd had when you broke down:

• Offset pliers
• small channel locks
• slip-joint pliers
• magnetic flashlight
• three standard 1" radiator band clamps
• (4) jugs of water... or in my case: one jug and a creek

I got lucky - I do maintenance work and have a ton of odd parts & more tools than most people carry and was able to bypass things easily... Roadside replacement wasn't really an option 35 miles from the nearest auto parts store and given the obscured location this valve is in.

Unhooking is a royal pain in the **** but if you have some SMALL channel locks (offset / adjustable mouth slip-joint pliers) and other pliers you can eventually disconnect the squeeze clamps used by feel. Each one depends on being able to maneuver your hand and the pliers in then find & grip the squeeze clamp. Once you manage it - you can raise the clamp up the hose but it's a pain-in-the-**** to find/grip/see/grasp/angle/invent-new-words.

Take a look at the old valve's orientation before you disconnect it as you'll have to hook it to the rear-most hoses first... and 'pre-orient' which way it is pointing so the remaining ports are lined up for remaining hoses.

You will be doing most of this by 'feel' & do NOT plan on it being a 1/2 hour job unless your engine is out and you can work from where the motor is usually at (...like the numbskulls who designed it to be first installed on the assembly line). It took me 4 hours of casual effort on a cold engine - just planned on staying home that morning until it was done. Now that I've done it I could easily halve that time and with some effort maybe even an hour... but without the right tools to grab those hidden clamps - square one & good luck.

Only posting this as I'm not the only one who asked & the OP never got his answer.