2nd Gen Non-Engine/Transmission Anyone replaced their heater core ????

[KOwens]

Hello TDR gurus,



The heater core on my '95 Ram Diesel sprung a leak and had been filling my cab wth swamp fog that smelled like funky coolant. I put a bypass in the heater core coolant lines so I could continue to drive it, but I want to fix it pronto if possible. I'm planning on tearing into it next weekend, and from reading the manual, I also need to separate the A/C evaporator lines in order to get the heater/air conditioning unit out from under the dash. I've got no experience with this particular kind of repair... on any vehicle for that matter.



Do any of you knowledgable mobile A/C guys have any crucial spiritual advice for a beginner like myself... so I might avoid some of the pitfalls... should there be any. Since the cost was going to be significant, I bit the bullet and bought a Robinair gauge set for R-134a, a vacuum pump, a digital thermometer, the garter spring expansion tools, and a puncture valve for recharging my system when I complete the repair. I also ordered and picked up the needed o-rings from the Dodge dealer that fit the evaporator lines. Other than that, all I have is courage... or is that ignorance? :-laf



Anyway, if you have any information or techniques that will make this repair less painful, I'd love to hear from you.



Thank you... Kevin

 

[JDougherty]

i know i have read extensive directions on tdr about this project. in fact somebody wrote in how to do it with out completely removing your dash.



try the search feature and hopefully they will chime in and tell you how to do it!

 

[MarkMiller]

*north south east west* God bless you my son. Amen. I had to do my a/c core (same spot as heater core) last summer. With a good helper it took me a full day. 9 am til midnight. Bloody wh*&^. The bolts on the outside of the firewall that hold something, maybe the fitting bracket, were a pain in the azz. I happened to have one of those hollow center rachets (O rachet) and it was the only thing that would get to them. Deep well was too long an shallow wouldn't reach and wrench was to big.



The little bolts inside, at base of dash where it meets the windshield are easy if you have a 2ft 1/4 in extension.



Make sure you pay close attention to how the box that houses the cores comes apart and how the vent flappers work. BE CERTAIN THAT WHEN YOU REASSEMBLE THE BOX THAT THE VENT CONTROLS ALL WORK. I got mine all back together and realized i hadn't completely seated a little guidepin and nearly had to tear mine back down completely. It wouldn't switch from ac to heat. A small screwdriver and a super skinny buddy with long arms saved me on that.



You also don't have to pull the entire steering column. You can just drop it out of the bottom of the dash and set it on the seat. I pulled my entire dash loose then used a strap to tie it up to the roof in my truck to get the core box offthe firewall.



Good luck, plan more than a full day.

 

[KOwens]

Thanks guys,



I'll search for historic info on this repair.



Also, sounds like a bit of tedious work... but I'm up for the challenge... and I can't imagine a repair shop taking the time to do it gently. Slam bang more likely. At least I will care about how the job gets done.



Does anyone have any comments of the A/C side of the show? Should I replace my evaporator at the same time... since it is also 10 years old... like the heater core? Can anyone tell me about breaking the A/C lines apart at the firewall? Is this a pain or do they come apart easily? I guess the A/C part of the show is more intimidating than the other tasks... simply because I have no experience in this area.



Anyway, if you can tell me more, I'd sure appreciate it. Go TDR !!!



v/r Kevin

 

[Joe G.]

Removing the seats is easy and really gives you more room to work.

 

[BigPapa]

I think it was Joe Donnelly that wrote an excellent article on this very thing, I think it was last year. I loaned my copy to a buddy that had to do his. My buddy said the article was GREAT help to him because it told him how to do it WITHOUT completely removing the dash and WITHOUT removing the A/C lines. I would definetly check it out. He hasn't given it back to me yet so I can't tell you what issue it was. I hope you can return those A/C tools.



Scott

 

[KOwens]

Thanks BigPapa,



Was this article in the TDR publication we get in the mail? I've got all my old issues... somewhere around the house. If you could determine the issue number, I could take a look, and try to find it.



I'm not too concerned about being the kid on the block with some A/C tools. Got lots of user in my immediate family who will get some use out of them. Anyway, thanks for the concern.



Kevin

 

[nps]

Here's a thread on the AC evap. But the steps are the same to get at the heater core.



Click Here

 

[Joseph Donnelly]

TDR #46, p. 12.

 

[KOwens]

Thanks Joe,



I'll look for this issue tonight when I get home from work.



By the way, do you feel I should replace my evaporator as long as I'm in this deep replacing the heater core. My '95 has 203,000 miles on it... all mine... and I'd prefer to do this repair just once if possible. Are there any statistics on how long the evaporators last... or does the old saying... "if it ain't broke, don't fix it" apply?



Any advice would be appreciated... and thanks again for your reply. I know you are somewhat of an icon within the TDR, and I value what you say.



Thanks... Kevin

 

[Joseph Donnelly]

Don't know about the evap core. You could remove it and have it pressure tested, or just look for any external signs of corrosion. If it were mine, I'd probably use its appearance and replacement cost as guides.

 

[Matt42]

Remove At Least The Driver Seat

Removing the seats is easy and really gives you more room to work.

I did this repair last year, also due to the swamp gas problem from the leaky heater core. As has been pointed out in other posts, it's not necessary to remove the entire dashboard or steering column. I loosened the dashboard to the point where I could rotate it downward and a little to the left, and then all was simple to get at. (Well, simple compared to untangling geophone cables. )



A few thoughts, if it's not too late. Some are redundant with other posts.



--Plan on a two-day job and don't rush yourself.



-- I wish I had removed at least the driver seat. That would have allowed me to lower the steering column just a few centimeters more, which would have made the job much easier.



--Before you dig into the dashboard, buy a set of the plastic screw inserts that snap into the top of the dash-cowl area. These are what the top front sheet metal screws go into to hold the top of the dashboard on. I couldn't find anything else that would work. There are four or five of them, and they'll set you back about $3 each. You may have to order them. It's worth the money. By the time your truck gets to the point where the heater core is shot, these little plastic inserts will also be shot (unless you live in Nova Scotia). If you don't replace them, count on strange dashboard squeaks and rattles. I replaced them and I have no rattles or squeaks. (Really. )



--The heater core will have a little metal ground contact that uses a nut to fasten to a 6 mm stud on the steel part of the cowl. It's to prevent electrolysis. The assembler had installed mine with way too much force, and the stud on the cowl was stripped. It was easy to get off, but ground contact had been intermittent and may have contributed to the failure of the heater core. Be sure to ground your heater core. You may need to fabricate a second ground wire if you use the suggested plastic-mounted heater core. I did, just to be safe.



--Buy a brand of heater core that's plated or anodized, and that has hose connections that are set into plastic so they can rotate a little to fit. You can get these from other than MoPar. I think mine is a Heater Pro.



--Replace the a/c accumulator when you have the system apart. You'll need to add about an ounce of the appropriate PAG oil. You'll also need a cheap set of plastic Ford-Type a/c connector ring tools. They are not expensive. Don't try to save money by using a pair of screwdrivers.



--If you find that you need a new a/c evaporator, do not try any brand other than MoPar. I tried to save $50 and ended up spending way more. Only the MoPar OEM evaporator has enough flex in the connector tubes to allow the fittings in the engine compartment to actually snap together. They may act tight, but they will not be. Holding a cheapie evaporator up against your OEM will illustrate the obvious differences. Do not skimp here. Even if you have to leave your truck's dash disembowled and drive your kid's Yugo while you wait for this part, it will be worth it. (I have an unused AirPro evaporator with ovalled fittings available cheap for the brave amongst us. )



--If you get black particulates in the a/c system oil, your compressor and condenser may also need to be replaced. (Phoenix traffic is miserable for air conditioners. ) However, you may be able to rescue the condensor by *carefully* pulling out the orfice assembly out of the fitting that faces *up* using small needle nose pliers. Clean it with a toothbrush and denatured alcohol, taking extra care to gently clean the tiny screen. Flush the condensor with denatured alcohol. Do not use drugstore isopropanol, or rubbing alcohol, since it contains about 30% water. Make sure it is dry before reinstalling, but do not blow it out with compressed air. (Contains a little water. )



--Make sure that you have a good 1/4 inch drive ratchet, a 1/4 inch drive handle, and a good supply of 12 mm and 10 mm sockets in standard and deep. You'll use the 10 mm deep socket a lot, and a deep wall version will work the best. You'll also need a thin, long, straight screwdriver to pry on the heater door control.



--Play soothing music in the background, make sure that the a/c system vacuum holds for several hours (I tested mine for 18), make an advance appointment with your chiropractor, and look forward to heat that isn't rancid.



Matt

 

[RHARVEY]

Mine is in the process of getting done right now! I had planned on doing the job myself but with my schedule I just didnt have the time to do it. After 239k on the stock one. . I guess it had done its duty



Rick

 

[CLeinbach]

'97 heater core/evaporator core replacement!

I did the heater core/evaporator core replacement about 2 weeks ago on my ’97 3500 Diesel. It most certainly was a bugger of a job but wasn’t too bad as long as you have a fair amount of time because you will get frustrated, at times. It took me several days because I wanted to be thorough, not do it again for several years, hopefully, and I work shorter days now (newly retired). A few more thoughts to add all of the excellent posts I read through.



My heater core went out during the summer but didn’t really have time because our youngest daughter was getting married in August so I just bypassed the heater with a piece of hose. Glad I did because then the evaporator core went out and their both in the same housing. We’re down here in Yuma and they wanted over $650 for labor for the job so there’s good incentive! Need the evaporator here and the heater core when we go back to Oregon. Joe Donnelly’s article in issue 46, page 12-15 is real good, as far as it goes, which is heater core replacement. If I was in that deep, I would go in and check the condition of the evaporator core (same age). If you notice a reduced volume of air flow on the 4th speed of your fan, it may well be because the blower air goes through the evaporator core before the heater core. Besides leaking (green dye from AC shop helps locate), the evaporator core was almost ½ plugged with leaf debris and apparently dog hair from the first owner’s (probably running on recirculated air from the cab). Joe has a helpful list at the end of his article with socket sizes.



Parts- Did some checking around, NAPA had a good price for a heater core ($107) and got it in one day but I didn’t like the aluminum core and “flex” crimped fittings that swivel (probably fits other trucks). It may well work fine for quite some time but didn’t want to wonder if the “swivel” gaskets would hold up more than a couple of years. Aluminum tubes were also roughly bent and gouged from their tube bender (China). AC shop part prices were between NAPA and Dodge but the “guaranteed” brass core wound up being same aluminum “flex” as NAPA after 3 day wait, GRRR. Dodge core (Taiwan) was way too expensive at $227 (they know what the competition core is) but it is a “direct” replacement for the old one with a nice core and nicely soldered copper tubes (saving on labor helped price of core!). Tubes were bent perfect and a little longer which makes for easier hookup. It also had all of the foam padding glued on so it will fit tight and stay put so it won’t vibrate around and leak over time. Be careful tightening the clamp at the tube/core solder connection so you don’t build in a strain that could leak, over time. NAPA evaporator core ($158) was cheaply made and one tube was bent about 15 degrees off needed bend (not much room for incorrect bend on this core) and again, no padding. Dodge core was $198 but perfect replacement with padding and tube insulation just like the original (this core was even made in the USA!!). Hate the outrageous prices (especially for foreign cheap labor parts) compared to the old days but what can you do (a lot cheaper than new truck payments).



I didn’t have a problem with dropping the steering column only onto the seat but really look ahead for strained wires (especially if you have added accessories) and the metal plate below the column also needs to be removed because sharp edges press against column wires with it dropped. I didn’t have a (major,grrr) problem with the 5 dash board top 10mm screws (thin deep wall sockets and extensions essential!) on removal but trouble with center screw on reinstall because dash was warped a little low in the center. Filing point on screw (and choice cuss words) got it back in (no squeaks, old Ford dash had bad squeaks!). Figure out how the cheap O-ring tool works, if you don’t know already, before you remove refrig lines (pretty simple, once you know). Be very careful with seal areas of tubing (I slightly gouged one tube end seal area I couldn’t see on disconnect and had to polish out with fine emory and crocus). Any flaw could cause O-ring leak. “Always” use new O-rings of right compound on refrig tubes and lube them with PAG oil (tubing “snaps” together pretty slick). I put 2 oz directly in the inlet of the evaporator core tube and 3 ozs in the new accumulator (Dodge book says 4 and AC shop said 2 so I put in 3 into the “inlet” tube). You have to remove the accumulator to access heater box nuts so replaced (AC shop said accumulator only good for 5/6 years (hmm) but want system to work good after all this. Again, NAPA part ($63, Dodge $126, double, hmmm) looked cheap (aluminum & China made may be OK but can’t see inside) but incorrect angle on outlet tube that may or may not have hooked up. You don’t want unnecessary leaks, vacuuming and recharging AC way too expensive for that! Remove and clean fixed orifice screen and regulator in condenser outlet tube end. Reach straight in “gently” with long needle nose pliers with “real” good serrations on the jaws, (don’t bugger up ID of tube, sealing area!), it will come out hard at first because of “O” rings. It is critical to keep water and crude out of all tubing and internal AC parts!! Keep tubing and parts clean and sealed until just ready for assembly!



Holding up right end dash board to remove and install heater/AC box is absolutely necessary! I was working outside so rigged a 2 X 4 across top of cab and open right door. Using rope and bungies, I held right dash end about 8 inches up and 6 inches back beyond dash “roll back” position to just have enough room to remove and install box (still a &@*_, watch all vacuum hoses, especially “two” on actuator on floor board and be gentle with temp control cable removal!). Left end of dash will behave, if you loosen left pivot bolt well and watch for wire strains around steering column and dash area.



Take your time and thoroughly clean the box of crude. Also I took the time to clean crude from cowl and wiper motor area or it may wind up in your new parts. I have pictures if anyone is interested or wants more info. Sorry for the length of this email but found other Members details very helpful. We now have Great AC and heat!! Take your time, think about the money your saving and good luck!

 

[Matt42]

I did the heater core/evaporator core replacement about 2 weeks ago on my ’97 3500 Diesel. It most certainly was a bugger of a job but wasn’t too bad as long as you have a fair amount of time because you will get frustrated, at times. It took me several days because I wanted to be thorough, not do it again for several years, hopefully, and I work shorter days now (newly retired). A few more thoughts to add all of the excellent posts I read through.



-snip-Great AC and heat!! Take your time, think about the money your saving and good luck!

Your post brought back memories. Not fond, but certainly vivid.

 

[Rip Rook]

Pressure check the new heater core PREVIOUS to install !