rechinca

My van is/was a 97 Express with a Glaval Gladiator conversion that is being converted into a covert camper of sorts. It had rear heat and AC. I already pulled the rear heater core and looped the hard lines under the driver’s side, but now those lines are leaking at the junctions up front. Go figure. I have heard people plumbed the lines out completely by changing the heater valves to the front only/two port style with the proper lines to. I am never putting it back to having the rear heater so this isn’t even up for debate. And the leak is getting progressively worse to the point I need to do something with it very soon. Has anyone done this removal / conversion to front only heat in a conversion van? If I missed the info or write up on it, I apologize ahead of time.

rechinca

Has no one out there done this change? I am pretty sure I saw that it has been done just no info. Otherwise I will continue. Plan is to remove valve and lines, replace with the two port valve and corresponding lines for with A/C and without auxiliary heat. It’s leaking pretty bad now.

William Kisselstein

I looked at eliminating the rear heater lines on a 2002. The line came off the engine and went to the rear, then came back into the heater box on the return. So you just buy the connector hose for a non-rear heat van for like $20 and put it on under the hood. Pray the plastic connector on the heater side doesn't break.

After that as long as you drain them you can let them hang if you want.

The A/C is another story, mine didn't have that so I don't know. My 1994 does but I presume it's entirely different.

rechinca

Ok, problem solved and crisis averted. I ended up having a broken heater control valve port as well as a crack in one of the hard lines going to the rear. Not a hard task, not an easy task but time consuming. I’d say budget at least a full day to a day and half to complete this.

What you will need to remove remove / bypass the rear heater:
1) Four port heater control valve (Murray # 74805). This replaces the six port valve and is for a van with AC but NO auxiliary heater.

2)Gates Hoses:
19773
28467
28468
28475

3) Spring clamp removal tool. One regular plier style and one cable operated version. About $40 total on Amazon.

Just do yourself a favor and remove a bunch of stuff now. Makes life a lot easier and the job will go smoother.

Remove the following:
Engine oil dipstick tube
Transmission oil dipstick tube
Alternator and the bracket the dipstick tubes mount to
Battery
Front of the AC evap coil/fan housing (you will need a 5.5 mm socket and wrench (the top 3 SUCK to remove)
Air intake/filter housing
Top half radiator shroud
Coolant tank

I drained the system via the lower radiator hose by removing from the water pump (no extended petcock valve on the radiator to attach a hose to)

I found a two part video from 1machine fix on YouTube about replacing the heater core that had great info on what needs to be removed that applies to my work as well as great still pic video from MikesTreasures that shows still shots on how the four port will need to be plumbed. For the most part is common sense, a couple lines will need to be cut to fit on the Valve to Heater core. The top of engine to valve line is a molded piece. YOU WILL REUSE THE LINE ON THE TOP OF THE WATER PUMP TO VALVE!!! But if the portion of the rubber line from to hard line to the water pump is bad or compromised, you can replace with standard cut to fit rubber line. This part is discontinued and I could not find one on short notice. I have pretty good mechanic skills, lots of tools and good sleuthing abilities so I rate this at a 5 out of 10 for difficulty mainly due to tight confines and those damned spring clips on the hoses. It’s just very time consuming. I also removed the hard lines from the engine compartment back to the crossover under the body. (They are hidden under a heat shield there and not accessible to remove. No harm leaving them there as they are empty now.)

rechinca

I have the kit to block off the rear AC lines in the engine compartment. I have not done it yet as I just need to get it to the shop to empty the refrigerant. Once that is done I will replace the condenser as I believe it had a small leak and has some damage Anthony ($100 for a new one). My shop said no charge to remove the refrigerant, $7/lb to refill. Since I am installing the condenser and block off fittings, I will only pay to recharge the system.

Oh, once you have the front of the evap/fan box off, it’s a great time to brush it off and clean it with some foaming cleaner. You'd be surprised at how dirty and packed it is with garbage. Your AC will cool better and flow more air now!

rechinca

These are screen grabs from the last video I mentioned from YouTube. You can see how much fun and how hard is to see the upper spring clamps on the heater core. This is why the cable spring clamp tool helps out. The conversion van / rear auxiliary heater utilizes a 6-port heater control valve. These pics show the four port you will use to eliminate the rear lines.

john2000

I plan to bypass the rear heater on my 2000 3500. I found this video which shows hose part number 88452 used to go between the control valve and the port behind the alternator.

I did use the rear heater once in my motovan to warm up a dirt bike on a cold morning while driving to a riding area. Worked great and bike started up easily. However, I'm planning a long trip and want to eliminate this potential failure point.

fortsumpter

@rechinca you have the same van as me. 1997 Chevy Express 1500 Gladiator conversion. I'm starting to remove the rear heater/ac unit now.. I know this isn't EXACTLY what your post is about but I'm wondering how you capped the AC lines. I plan on looping the heater lines and going to pray I don't have that same leak as you.

Did you cap the lines like this guy's video shows?
He mentiions it being the same for 02- current, Wasnt sure if this exact method would work for the 97 as well. Having trouble locating those exact ports that he capped.

These appear to be the fittings and look more like what I'm looking at under my hood.



Interested in hearing your experience if you get a chance! Thanks

john2000

I completed work on the bypass and removal of the rear HVAC unit. Having spring clamp pliers made the job much easier and I highly recommend having these. If there’s ever a next time I will purchase angled spring pliers to have more options when working in this tight area. Did not have to remove the plastic drain piece but did have to remove the alternator to access port on block. I purchased an AC blockoff kit on eBay for around $45 and it came with clear instructions. Also removed some of the leftover tubing to prevent rattles. Installed a new heater control valve to replace the original 23 year old valve while doing this job as I don’t want to be doing this again anytime soon. Feels good having a simpler system with all new hoses.