How to block off the rear AC using an AC block off kit
Learn how to use a rear AC block off kit to permanently seal the rear evaporator
Over time, the rear evaporator may fail due to corrosion, leaks, or clogging, necessitating a replacement. Replacement is an expensive option, so many owners of older trucks prefer to cut the high and low-pressure AC lines and permanently block them off. To do that, you’ll need a suitable rear AC block off kit.
What is a rear AC block off kit?
Two types of block off kits:
• Compression caps— Cut the line and install a compression ferrule and a cap.
• Fitting kit— Connects to the fitting already on the end of the line where it meets the evaporator. No cutting involved
Compression style block off kit caps pros and cons
Compression caps are easy to install and allow you to work in uncramped areas under the vehicle. Clean the line. Cut it, and install the cap.
Pros: • Less expensive than fitting kit. • Allows you to work anywhere under the vehicle.
Cons: •Because the system is under such high pressure, the block off kit can blow off the high pressure line if not installed properly. • It’s a permanent solution. If you every want to repair the rear evaporator, you’ll have to run new lines or splice in new line sections.
How to install a cap-style kit
To install, evacuate the system and cut the AC lines near the rear evaporator. Then install the rear AC block off kit on the liquid and suction lines.
The brand I use is made by AirSept. You’ll need to measure the line diameters or consult a shop manual.
Where to buy these AC line termination block off kits
SAE REAR AC BLOCKOFF KITS
Line Terminator Rear AC Blockoff Kit
1/2” OD Line AirSept 76501
Line Terminator Rear AC Blockoff Kit
3/8” OD Line AirSept 76502
Line Terminator Rear A/C Blockoff Kit
5/16” OD Line AirSept 76503
Line Terminator Rear AC Blockoff Kit
5/8” OD Line AirSept 76504
Line Terminator Rear AC Blockoff Kit
3/4” OD Line AirSept 76505
METRIC Rear AC BLOCKOFF KITS
Line Terminator A/C Blockoff Kit
8mm OD Line AirSept 77508
Line Terminator A/C Blockoff Kit
10mm OD Line AirSept 77510
Line Terminator A/C Blockoff Kit
12mm OD Line AirSept 77512
Line Terminator A/C Blockoff Kit
15mm OD Line AirSept 77515
Line Terminator A/C Blockoff Kit
16mm OD Line AirSept 77516
Fitting style block off kit caps pros and cons
Pros: • No cutting. Because these kits are installed onto
Rear AC Block Off Expedition, Navigator 10-18 F
the factory ends, there’s no cutting involved. Just disconnect the line from the evaporator and install the block off kit. If you ever decide to replace the leaking rear evaporator, just remove the caps and connect the lines to the new component. No need to splice the lines.
Cons: • More expensive than a cap kit. • You’ll have limited working space because you have to install the kit right at the rear evaporator
How to install a fitting style block off kit
Evacuate the system
Disconnect the high and low-pressure lines from the rear evaporator
Install the caps.
Where to buy fitting style block off kits
©, 2015 Rick Muscoplat
Posted on by Rick Muscoplat