HOW TO: Quick Disconnect Delete (AKA how to fix the leaking quick disconect fitting)

[Nas Escobar]

Mods: If this thread is found to be useful, please move to the proper category so others can find it easier. Thank You.

 

This post will deal with one of the more annoying features of the 60 Degree V6, more particularly the LQ1. As luck would have it, we're not the only ones with this issue but our cars are more suspectable to be sent to the junkyard than those with a 350SBC (A well known engine that has the heater hose quick disconnect fitting) This is the "Quick Disconnect" fitting that is located on the lower intake manifold (LIM for short) and has a tube that runs to the heater hose by the brake booster (or at least, that's how it's configured on the LQ1. I cannot speak of the 3.1MPFI nor the 3100 SFI as I do not own one).

 

If your engine uses the DORMAN 800-401 quick disconnect fitting, this post is for you. If your engine does not use this fitting, then this post is not for you. You can continue reading to get an idea of how to fix your quick disconnect issues (which is basically just using a barb fitting to replace the quick disconnect) but this is to delete the DORMAN 800-401 fitting.

 

This mod/fix is an alternative to replacing the Dorman 800-401. More often than not, this piece leaks right where the plastic clip that holds the tube to the heater hose fitting is pressed in.

 

I will describe how to convert that piece from a Dorman "Quick Disconnect" hose, to an old fashioned hose and worm clamp fitting, like so.

 

[photobucket ruined the link, will update soon]

 

Materials you will need:
 

1/2 ratchet

3" extension (OPTIONAL)

27mm 6 point socket (Deep is better, but shallow works too)

Teflon Tape (also known as plumber's tape)

5/8 in ID x 1/2 in MIP barb fitting. You can source this piece from the Home Depot or Lowe's. HD part number is LFA-493.

3/8 Ratchet (may be able to use 1/2)

19mm or similar socket

3 feet of 5/8 hose (or you can measure how much you really need, I only needed 26")

2 worm clamps 

1/4 ratchet

7mm or similar socket, depending on the size of your worm clamp's screw

1/4 3" and 6" extensions, as this will help reach into that area more comfortably

Flathead screwdriver (may or may not help)

Extra anti-freeze/coolant mix

 

Step 1: Disconnect MAF sensor (94+), IAT sensor, vacuum lines and any other accessories on the intake tube.
 

Step 2: Remove the air filter box and intake tubing. If you have replaced your air box with a cone filter, remove the intake tube. You may have to remove the MAF (if so equipped) to move around the intake tubing and air box more freely. You may or may not have to actually remove the air box. The goal here is to have room under the throttle body, where the quick disconnect fitting is located.

 

Step 3: Locate the heater hose disconnect and place a catch pan, bucket, tupperware, bowl of choice under the heater hose.

 

Step 4: Remove the heater hose pipe at the quick disconnect by pressing on the clip in an inward motion and pulling out. If you're lucky (or better said, if your engine has already emptied itself via that tube) you probably will only get a couple drops out of that tube.

 

Step 5: Drain bowl of choice in a designated coolant storage pan for proper disposal (AKA I'm not responsible if you let the coolant go in the drain and you get caught/ticketed for it. Always dispose of fluids properly).

 

Step 6: place bowl of choice under the quick disconnect fitting (Once removed it does leak a bit)

 

Step 7: Remove the quick disconnect hose fitting with the 27mm socket.

 

Step 8: Once all coolant is out of the LIM, drain the bowl of choice into your designated coolant storage pan and set aside.

 

Step 9: Wrap teflon tape around the barb fitting. Remember, the 1/2" is the size of the thread side. 5/8 is the size of the barb where the hose goes.

 

Step 10: Thread in the barb fitting into the socket with your fingers. Make sure it is in straight and not crooked as a crooked fitted barb fitting will mess up the threads.

 

Step 11: Once verified that the barb fitting is straight and will no longer finger tighten, use your 19mm (or similar) socket and tighten barb fitting until tight. If you wish to torque it, please torque below the recommended torque spec for the quick disconnect fitting. Remember this isn't an OEM part, so take caution. 10lb ft torque should suffice.

 

Step 12: Remove the hose at the heater hose pipe

 

Step 13: Measure and cut your 5/8 hose then fit with worm clamps

 

Step 14: Slide the hose on the barb and tighten the worm clamp with the 1/4 socket. Socket size and extensions needed may differ on your selected worm clamp and socket location. I was able to get it using a 7mm socket and a 6" extension fitted through a passageway under the throttle body.

 

Step 15: Place the 5/8 hose on the heater hose pipe nipple and tighten the worm clamp there.

 

Step 16: Fill radiator (and reserve bottle) to appropriate levels.

 

Step 17: Check for leaks. No leaks = a successful fix!

[tsilney]

Genious! Wish I knew about this earlier. Just replaced mine a few months ago! Nice work.

[Nas Escobar]

Thank you.

 

I found out about it from a Chevy truck forum. Apparently the leak is more common on those things (as well as the fitting breaking at the threads) and someone along the way said that he replaced it with a barb. I had nothing to lose but the leaks so I tried it. Had to run and get barbs a couple times to get one that fit snug without force but all is well.

 

I've had the car with the barb since December of 2014 and there has been no issues in regards to water flow or the heater messing up since it gets more flow since the fitting apparently had a "restrictor". I personally think the bends in the hose itself act as a restrictor. There's a sharp bend where it comes up from the LIM.

[Schurkey]

As long as everyone understands that the worm-clamp is less reliable than the original (or replacement) quick disconnect, this is all fine. Rubber hose tends to cold-flow; and the worm-clamps most often used don't have a steel band to cover the slots in the clamp the worm gear pulls against. The result is that the hose flows through the slots in the clamp; and the hose leaks. The quick-coupler or quick-disconnect was an attempt to eliminate the problems involved in directly clamping a rubber hose.

 

In MY garage, I would (and did!) simply install a fresh quick-coupler. The only real problem with them is that the material is of poor quality--easily-corroded metal. The quick-disconnect corrodes and then leaks, or the rubber seal fails. Replacement completely fixes that problem when combined with proper coolant changes to eliminate acidic coolant that promotes corrosion.

[Nas Escobar]

I feel the 1st statement is relative to how bad the person's issue is with that quick disconnect. I had issues with that thing since the first LIM gasket change. The issue was never the actual fitting that goes into the LIM but the piece of plastic that holds the pipe that goes in the fitting. I had swapped out the fitting and plastic piece 5 times and had the same result (leaks at the plastic disconnect clip). At that point, I was insane since I was doing the same thing expecting different results. So I stopped defective exchanging the piece and this was born. I used the spring clamp on the tube by the brake booster that goes to the heater hose and the only worm clamp on it is under the throttle body. I would have preferred a spring clamp there too but couldn't find the right size at the parts store.

 

Come to think of it, I know those worm clamps aren't the best thing. I never liked them because the screw usually messes up and won't tighten after a certain point or gets out of line. I currently have that problem in a Jeep where the worm clamp on the trans line to the radiator pops off after a while. It's the most annoying thing to deal with when all that fluid comes out. I've been trying to figure out a solution for that before it fries my transmission.

 

Anyways, when you talk of installing a fresh quick coupler, are you mentioning that plastic piece in the fitting or did you retrofit the piece with something else?

[Schurkey]

I feel the 1st statement is relative to how bad the person's issue is with that quick disconnect. I had issues with that thing since the first LIM gasket change. The issue was never the actual fitting that goes into the LIM but the piece of plastic that holds the pipe that goes in the fitting. I had swapped out the fitting and plastic piece 5 times and had the same result (leaks at the plastic disconnect clip). At that point, I was insane since I was doing the same thing expecting different results. So I stopped defective exchanging the piece and this was born.

First Guess: Defective O-ring that the "plastic piece" seals against.

 

I currently have that problem in a Jeep where the worm clamp on the trans line to the radiator pops off after a while. It's the most annoying thing to deal with when all that fluid comes out. I've been trying to figure out a solution for that before it fries my transmission.

ATF leaks might fry your transmission, but the REAL problem with ATF leaks is that ATF is surprisingly flammable. Frying the trans is preferable to baking the entire vehicle due to an under-hood fire.

 

Anyways, when you talk of installing a fresh quick coupler, are you mentioning that plastic piece in the fitting or did you retrofit the piece with something else?

I installed everything that came in the Dorman (Help) kit. Therefore, metal body and O-ring that threads into engine, and plastic piece that pops onto the tube.

[Imp558]

Simple fix, good work Nas. I agree this should be a FAQ.

[Psych0matt]

Simple fix, good work Nas. I agree this should be a FAQ.

i couldn't for the life of me get it to seal on the gtp, so I replaced it with a solid fitting

[Nas Escobar]

i couldn't for the life of me get it to seal on the gtp, so I replaced it with a solid fitting

 

You and I both. I didn't even try it on the Z34, I went straight for the barb fitting.

[snippits]

 

Very good article!

I am in the process of changing a heater core on a 92 Cutlass Supreme S with the 3.1 LHO VIN T engine.  Replacing all the heater hoses too since they are getting old, and I might as well replace or modify the 800-401 heater hose connector.

I only see one problem by doing the mod on my 3.1.  The 5/8 heater hose that runs from barb to lower tube on heater core is going to be subject to lots of heat from the exhaust manifold.  That's the reason there is a metal pipe to the connector, and then a formed hose on the other end of pipe to the heater core.  If I did do the modification, the 5/8 heater hose would have to be in a heat sheath, and Advance Auto has one in stock that is 3/4" x 3'.  

https://shop.advanceautoparts.com/p/design-engineering-heat-sheath-aluminized-sleeving-3-4-x-3-010403/16120024-P?navigationPath=L1*14932|L2*14983|L3*15320|L4*-49996485

I don't worry about using the original band clamps any more for heater hoses.  Once I started using Norma Torro worm drive hose clamps, cold leaks went bye bye, and they don't tear up the hose either.

https://www.normagroup.com/norma/en/products/norma-torro/

Edited July 11, 2020 by snippits