2nd Gen Non-Engine/Transmission Replace Evap.

[TXDSLSHOP]

I have a leak in my A/C which I can't find with dye. I figure it is in the Evaperator and I am going to replace it. I know it is a hell of a job but I am on Baby leave and have a couple days I can devote to the job. Can someone please send me instructions and/or tips to take some of the pain out? I would really appreciate the help. If anyone is in my area and works for beer, let me know! Thanks again. Jeremy.

 

[Walt-L]

I did the evap core a few weeks ago in my 01 and found it wasn't as bad as most made it out to be. I will post my notes here one of these days. Your 98 dash is a bit diferent than mine but here is a basic version. Take the knee panel off, take the air bag modual and bracket out from between the hump in the floor and the bottom center of the dash. Take the glove box out by bending the back inside panel of it in to the fire wall. this will get one off the box's stops to pop out foward then the other. from left to right, unhook the emergence brake handle only. take the side kick panel out and loosen the 13mm bolt behind the kick panel that the dash frame comes down onto. (the right side has the same 13mm bolt, the dash will rock back away from the cowl using these 2 bolts as pivots later. ) Now remove the 2 10mm nuts that hold the stearing wheel body to the dash frame and let the stearing wheel come to a rest on the drivers seat. Take the right side kick panel off and loosen that other 13mm bolt there. Get some rope and a expansion jack (2x4) about 2' long or so. The last step on the dash is to remove the small bolts along the top of the dash under the glass. this will let the dash loose to where it will fall/pivot back away from the cowl while pivoting on the 2 13mm side bolts that you left in a loose condition. at this point be ready to prop up the right side of the dash by about 8 inches above its normal position AND back away from the cowl by about 6 or 8 inches. you will have to now REMOVE the 13 mm side bolts to get the right side of the dash to ccock back and up like this all the while leaving the left side of the dash pretty much alone. Now with the right side of the dash proped up like this, you have 2 10mm nut to get off the HVAC box on the inside. One has a ground strap under the one and the second is on a vertical stud this side of the door hinge post. NOW unhook the vac lines to the 2 acuators above the go petal. Now go under the hood and you have to take the air box out, then the PCM off the fire wall to the right of the air box. here you will need to take off the remaining 4 10mm nuts holding the HVAC box on the fire wall. One is near the valve cover another is behind where the PCM was mounted to the fire wall and the other 2 nuts are near where the ac pipes come through the wall. You also have a black vac line on a rubber elbow here that you will have to unhook so the vac line will pull back through the firewall when you pull the HVAC box loose and out from under your proped up dash. You will need a vac line tool to pop the vac lines apart. Napa has one for 18 bucks. Don't forget to replace your dryer canister that fits in the mount on the firewall along with the evap core. AND dont bother bying a recharge R134A can at the store because once you get the thing put back together you will need a shop to vacumm out the system with a special machine BEFORE you can recharge the system. You will see that many of the things that others say to remove from the dash is simply not nessesary to get the job done. Good luck.

 

[trqmnstr]

Good post Walt. With my new found confidence I think I will tackle the evap on my own. How long did it take you to complete?

 

[Walt-L]

Its hard to say how long it took because I had read you have to take the emergency brake completely loose and I also read you had to remove the instrument cluster (which I almost did) and remove the radio, which i did. ALL of which are not nessesary. Also I have mounted my boost and pyro gauges into the dash bezel so I removed them before I found out the left side of the dash does not move far enough away to justify unhooking any thing there. Knowing what I know now, I would guess you can do the job in less than 4 hours with a good screw gun.

I would also urge any one who is to do this job to drain the radiator (you have to drain it down some to unhook the heater core), remove it, and clean it. You would be amazed at how badly my radiator was pluged (nearly 20 percent) on the front from the oil fumes of the vent drip bottle with 100K on the clock. The rad comes out REALY EASY after you take the fan clutch/fan assembly out first by braking the single fan clutch nut loose with a vise grip chain wrench, large nut wrench and pipes for leverage. Then the washer bottle and overflow bottle, then the shrowd, then 2 radiator bolts at the top and out it comes! It is ABSOLUTLY important your rad can move air through it not just for your engines sake but you intercooler AND oil cooler AND AC! Buy lots of easy start spray cans. and garden hose on low pressure straight at the fins to blow all the crap out.

NOW, once I had the rad out I came to realize how incredibly easy it would be to fix the oil seal on the VAC pump. Here you have LOTS of room to slide the VAC/Power stearing unit straight back(after you take 3 of the 4 nuts off that hold the PS unit on to the VAC pump) the fourth near the block comes off once you take the vac unit loose from the case, separating the power stearing unit from the vac pump on the vehicle. Most will tell you you have to "cut" the power stearing lines and take the vac/ps unit out together. NOT SO with the Rad out of the way! You simply take the Vac pump off a un molested PS assembly, rebuild it on the bench with Cummins $8. 00 rebuild kit(with instructions) and slide it back onto the intact PS unit right on the truck. Now my right side engine block is absolutely oil free! Here again I NEVER would have wanted to try this without the rad out of the way. Black an white/ day n night differance over other peoples struggles with this one. Sorry for the long rant but I hope some other "timid" shade tree mechanics like my self will find this of great value.

 

[JMetzger]

One thing you could do before you to all that work is borrow or get a leak detector & run the a/c with the fan on low or med and insert the leak detector in the middle duct & if there is a leak in the evap the leak detector will pick it up.

 

[Walt-L]

JMetzger, Thats a great suggestion since I wasn't aware of a detector like that. The Evap I took out had a lot of corosion on the bottom 2 or 3 aluminum stack plates along with a bunch of debree. I am planing to fit a cab air filter or filters into the cowling openings under the plastic cover. My VW TDI Golf has one and a friend of mine said his Sable Wagon uses a cab filter. Im sure a internal mod like this or Geno's surface mounted filter will extend the life of these aluminum evaps.

 

[JMetzger]

That is a good idea, just don't get the filter material to fine or you can have problems with the a/c cycling a lot. Geno's would be good

JMetzger

 

[TXDSLSHOP]

Thanks for the responses, I have not done the Sniffer yet but I will before I tear it down. I just know how my luck goes, usually I just figure on the worst case scenario and it usually is! Thanks again guys, I will let you know how it comes out.

 

[nps]

TTT for Bob.

 

[Walt-L]

Heres a picture of the dash proped up and bungyed to the sill handle while the drivers side just lays loose in place while the HVAC unit slides back and out from under. http://www.dieseltruckresource.com/pics/showphoto.php/photo/10860/password//sort/1/cat/500/page/1

 

[TXDSLSHOP]

Done, piece of cake!

I finally took the time to replace my evap. today. I started at around noon and finished everything except recharge by around 4:00 or so. I worked steady and even took the time to replace the other o-rings in the system. I replaced the drier and added 2 oz oil to both the evap. and the drier for a total of 4. I then pressured the system with shop air and let it sit for and hour while I ate dinner and no leaks. I then pulled it down to 30 inches vacuum and let it dry for half hour. 2 pounds 134a and presto chango 44 degrees F. at idle and quite nipply! I really didn't run in to any snags thanks to Walt-L's great description. Maybe make sure you disconnect the vacuum connector above the go pedal before you tilt the dash. Thanks again Walt-L!

As I said in an earlier post I didn't think it was a big deal and would do it again, no problem.

 

[Walt-L]

Killer59, I'm glad it worked out for you. All the dred people have on this one is rather unfounded. We saved our selve's a good 5 bones pluse! and my AC is working great also.

 

[TXDSLSHOP]

I agree with you, I don't know why I put it off for a month. Oh well, it's done now and works alot better. Feels like twice the airflow. Thanks again. Jeremy.