Loslam
Newbie
Hey guys, long time forum guest viewer for help and information, new member. My goal is for this post to be helpful enough to be a sticky.
Very simple fix, the annoying plastic quick disconnect that is well known to cause anti-freeze leaks where the heater hose connects into the intake manifold. The problem I found when researching a permanent fix, is that no one gave enough full information or pictures to help a common folk out. So I'm doing that here!
We'll start with parts needed to remove the quick disconnect fitting entirely and replace it with one you don't have to replace yearly. (Note: I'm doing this on my '97 5.7 vortec which has the fitting on the front passenger side of the intake, but I believe all obs have this fitting and the TBI was on the rear of the intake)
All that is needed is the barbed fitting, and 1/2"-1[SUP]1[/SUP]/[SUB]4[/SUB]" hose clamps. For the barbed fitting, any 5/8" I.D. barb to 1/2" MIP/NPT thread will work. I got a brass barbed fitting from Lowes (P/N: LFA-493) and hose clamps from Autozone. (When all was said and done, the I.D. of my heater hose was actually 3/4" but Lowes didn't carry a 3/4" barb to 1/2" NPT, however you can find them online. The 5/8" I.D. barb did work fine just required tight clamps)
On to the pictures!
Only parts bought (less than $10 total):
Here's what the quick disconnect and fitting look like (forgive my phone's camera, not sure what happened here):
Before removing the old fitting, I would highly recommend spraying it with some penetrating fluid, I used PB blaster. Be very careful, it's known to break off easy. The socket/wrench size of the fitting is 1[SUP]1[/SUP]/[SUB]16[/SUB]", I used a 3/4" drive ratchet with a deepwell socket and it did me fine, no breaking off:
I wrapped the threads generously with teflon tape on the new barb fitting. Here it is compared to old fitting:
There are a few ways to go about the heater hose itself. You could buy another one and keep the stock with the aluminum crimped end. Myself, I found the easiest/cheapest way was just to cut the hose right before the aluminum crimp. This way I can just attach the hose straight to barb and clamp it. Simple. I used sheet metal scissors, easy:
Here is the new barbed fitting screwed in. Very tight and sealed with teflon tape. I would also be careful here if you go with brass, and not screw it in too tight. This particular fitting had a 13/16" hex, and I used a spark plug deep well socket with a 1/2" drive ratchet:
I put a generous amount of hi-temp red silicon around the barb (be careful not to put inside hose, you don't want silicon blocking your coolant flow). The 5/8" barb was just a little bit too small inside the heater hose, but with the silicon and the two clamps very tight, it was fine. If I redid this or this is your first time, try to find a 3/4" barb to 1/2" NPT for a perfect fit of the hose. I then wrapped most of the heater hose with some conduit (my hose ended up being a little closer to headers). Here is the finished result:
From the top:
And finally, here's the old crappy design that I had so many leaks from removed:
It's been about a week now, and not a single drop of anti-freeze from the new fitting.
Wonderful forum! Hope this helps some peeps and guests!
Very simple fix, the annoying plastic quick disconnect that is well known to cause anti-freeze leaks where the heater hose connects into the intake manifold. The problem I found when researching a permanent fix, is that no one gave enough full information or pictures to help a common folk out. So I'm doing that here!
We'll start with parts needed to remove the quick disconnect fitting entirely and replace it with one you don't have to replace yearly. (Note: I'm doing this on my '97 5.7 vortec which has the fitting on the front passenger side of the intake, but I believe all obs have this fitting and the TBI was on the rear of the intake)
All that is needed is the barbed fitting, and 1/2"-1[SUP]1[/SUP]/[SUB]4[/SUB]" hose clamps. For the barbed fitting, any 5/8" I.D. barb to 1/2" MIP/NPT thread will work. I got a brass barbed fitting from Lowes (P/N: LFA-493) and hose clamps from Autozone. (When all was said and done, the I.D. of my heater hose was actually 3/4" but Lowes didn't carry a 3/4" barb to 1/2" NPT, however you can find them online. The 5/8" I.D. barb did work fine just required tight clamps)
On to the pictures!
Only parts bought (less than $10 total):
You must be registered for see images attach
Here's what the quick disconnect and fitting look like (forgive my phone's camera, not sure what happened here):
You must be registered for see images attach
Before removing the old fitting, I would highly recommend spraying it with some penetrating fluid, I used PB blaster. Be very careful, it's known to break off easy. The socket/wrench size of the fitting is 1[SUP]1[/SUP]/[SUB]16[/SUB]", I used a 3/4" drive ratchet with a deepwell socket and it did me fine, no breaking off:
You must be registered for see images attach
I wrapped the threads generously with teflon tape on the new barb fitting. Here it is compared to old fitting:
You must be registered for see images attach
There are a few ways to go about the heater hose itself. You could buy another one and keep the stock with the aluminum crimped end. Myself, I found the easiest/cheapest way was just to cut the hose right before the aluminum crimp. This way I can just attach the hose straight to barb and clamp it. Simple. I used sheet metal scissors, easy:
You must be registered for see images attach
Here is the new barbed fitting screwed in. Very tight and sealed with teflon tape. I would also be careful here if you go with brass, and not screw it in too tight. This particular fitting had a 13/16" hex, and I used a spark plug deep well socket with a 1/2" drive ratchet:
You must be registered for see images attach
I put a generous amount of hi-temp red silicon around the barb (be careful not to put inside hose, you don't want silicon blocking your coolant flow). The 5/8" barb was just a little bit too small inside the heater hose, but with the silicon and the two clamps very tight, it was fine. If I redid this or this is your first time, try to find a 3/4" barb to 1/2" NPT for a perfect fit of the hose. I then wrapped most of the heater hose with some conduit (my hose ended up being a little closer to headers). Here is the finished result:
You must be registered for see images attach
From the top:
You must be registered for see images attach
And finally, here's the old crappy design that I had so many leaks from removed:
You must be registered for see images attach
It's been about a week now, and not a single drop of anti-freeze from the new fitting.
Wonderful forum! Hope this helps some peeps and guests!
Last edited: