1999 s70 Evita AC evap replacement (July 2025) [12 hours, $150 parts] Topic is solved

[abscate]

Trying to do evaporator on Abby’s car , she works home Friday Monday so started on Thursday night to hopefully have car ready for Tuesday! Flashback to 2013 when I did my first AC job ever!

viewtopic.php?t=56005&start=40

Evita is a 25 year old s70 which my daughter daily drives. We got her in 2018 with a stuck engine, freed it up and she drove her for college, and now for her first two jobs. She is the only person in her office under 30 without a car payment, good for a $5000 after tax raise at work. She inherited my “ don’t do heat well “ genes and has been suffering no AC for two years. I decided this car deserves the attention given how well it has served us; college, then a 4x minute Long Island commute for two years, now a 5 minute commute

Wiki of job hours - trying to beat 10 hours all in.

Day one - two hours to get dash out

Day two 3 hour to get HVAC OUT AND evap replaced.

Day 3 1 hour to get all the bolts and old parts ready for install

Day 4 1 hour , install new Nissens heater core , install HVAC system into car. Broke the heater firewall interface, new one FCP $350
New one in stock, free


Day 5 2 hours for dryer, hard lines, suction line…..pumped down and system pegged vacuum gauge, held with no leaks for 4 hours, do no gross leaks.

Day 6 2 hours of electrical plugs, \dash hardware, and charging AC while doing same

Day 7 - I will need one more hour to sort out console and rest of fittings.

Achieved 40F delta with AC on ambient 84F day, at 2500rom, fan 3, RECIRC

GRAND TOTAL 12 hours, $150 in parts.

Forgot to remove the ECU cooling hose which was tight and hung up HVAC. On my other cars it would pop off easily

I forget to pop the climate filter gaiter off the cowl which hung up climate unit removal.

Her car has the nice amp so there’s a module in the way of the heater core T20 screw , three m8 13mm hex to remove

Job note..you need two sets of evap seal to fully seal the evaporator into the hvac. Part 9171783
Install the core, rubber gaiter, sliding door into the top of the hvac , then slide it into the unit and do the clips/t10 torx screws

You really need two people to remove dash. I fought it solo and that was stupid. Get help. It’s bulky, heavy, and fragile

Link to the master oring thread for part numbers for all those little orings in this job…

viewtopic.php?t=88579&hilit=Master+ac+oring

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[font=]oScope of work. I’m replacing evap due to leak, found her heater core was seeping so will do that too.

I would like to replace the drier but might have to defer that if the bolts don’t come nicely

Nasty leaky evaporator core

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More pix , captions to come

Note the hose technique to flush the heater core with water, this keeps you from having a coolant mess in cabin when you disconnect heater core. You could blow air to minimize that too.

Note the 3 minute technique to remove the old evap pipes. I hope to get the hard lines out onto the bench to complete removal of those pieces

I used some 1/4 thick weatherstripping to get a good seal on the evaporator in the case, the Nissens attached stuff was a bit skinny. You want a good seal for good AC or else the air flow will bypass the evaporator and kill the performance.

[abscate]

Here’s my usual strategy on AC evaporator replacement, addressing the pain points

Cut the old aluminum lines at the firewall with a small hacksaw. Make sure you cut at the narrowed part so you don’t bugger up the hard line. 57.3 seconds with hacksaw for each line. If your hacksaw isn’t moving down 1mm with each stroke on soft aluminum , you are on the steel line. It’s easy to see the narrower part where the steel one ends on inspection

I’ve never gotten the big nut off the dryer in my life while still on the car. It’s a big dry union nut , it rusts in, and the dryer mount is too flimsy to take torque. I undo the hard line at the compressor. The two hex 6mm bolts behind the right headlight that hood in the hard lines, the m6 10 mm hex nut holding the dryer canister in , and get the whole assembly up onto the bench. User cn90 nicely documented the way you get to the m6 hex internal on the compressor here. You might have different hardware in your compressor if it been replaced from OEM

viewtopic.php?p=278184&hilit=27mm#p278184

That makes removing the last two bit of aluminum evaporator line easy too. You can get eyes on the gaiter spring and get it moving with a pick before ypu expand and pull the line

Replace all the bolts and orings with fresh hardware of course. The $20 extra parts will thank you next time here are the three bolts you need. https://www.fcpeuro.com/products/volvo- ... lvo-959220

I sure do like modern cars where the spring design is replaced with a block and o-ring seal

You need two kits of orings to do this job. The single kit will leave you short

[scot850]

Ah, you bring all the nightmares back when I had to do this job on an 850. Getting those connectors separated at the bulkhead were just horrible. I like your approach. My difficulty was replacing those 2 connections as the Behr Evaporator cones were too large to allow the wire rings to get over them. Had to carefully file them down until the eventually fitted. Took almost a day for that.

I admire you sir!

Neil.

[abscate]

Got all three m6 hex bolts out of the hard line and compressor hose fitting without drama. Had to go to the KOBalt test of fluted nutgrabbers on all three as the internal hexes were not going take the break free torque. All of this hardware will be replaced, it’s all my hex by 20mm threaded shaft length on the two hardline bolts amd the compressor suction valve bolt

M6 10mm hex releases the dryer from the clamp, then 30 seconds MAPP gas and two big pipe wrenches to undo the 27mm dryernut, 24mm counter hold out……nasty ‘’

Getting the Aluminum stubs out of the hard lines was tough. Had to Dremel slots into them to get them out. Dryer connection came easily

I cut the dryer hard pipe to get out the hard line

End result two hours

Dryer out
Hard line high pressure out
Hard line low pressure out.
Compressor suction line out.

We are ready to start reassembly !

Note the picture shows the correct orientation of the suction pipe with respect to the dryer mount plate , it doesn’t have to be perfectly right, but get it to with one cm. There is enough play in the line to allow easy compressor attachment of the fitting

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Job tip. Once you get the m6 off the compressor, and dress the big suction hose up, you can get the whole high pressure hard line and dryer assembly up and out of the car working around the front of the engine.

All jobs are easier on the work bench.

[volvolugnut]

Got all three m6 hex bolts out of the hard line and compressor hose fitting without drama. Had to go to the KOBalt test of fluted nutgrabbers on all three as the internal hexes were not going take the break free torque. All of this hardware will be replaced, it’s all my hex by 20mm threaded shaft length on the two hardline bolts amd the compressor suction valve bolt

M6 10mm hex releases the dryer from the clamp, then 30 seconds MAPP gas and two big pipe wrenches to undo the 24mm dryer union nut , nasty ‘’

Getting the Aluminum stubs out of the hard lines was tough. Had to Dremel slots into them to get them out. Dryer connection came easily

I cut the dryer hard pipe to get out the hard line

End result two hours

Dryer out
Hard line high pressure out
Hard line low pressure out.
Compressor suction line out.

We are ready to start reassembly !

You can't fool me! That is genuine USA made Rigid Pipe wrench. Their pipe wrenches are known to survive long cheater pipes that bend the handle end without breaking the head.
volvolugnut

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Those Rigid tools are things of beauty. They made a quick work on that fat union nut.

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Managed to break up the bulkhead connector on the heater hoses reinstalling the HVAC

These have gotten expensive , $350 for the full kit, $175 for the firewall connector.

I am trying to remember the install procedure priority here. I think you want to remove the heater pipes from the bulkhead to install the unit, then go back and put the top ends in, the the bottom end with the T20 ? Screw