Heater return line leaking in valley, fix?

[JetmechF16]

FIX IN POST #6


I'm getting a decent pool of coolant in the intake valley clearly coming from the heater core return line that fits over the boss behind the water pump. I don't want to just replace the o-rings so what is everyone doing to delete this?

I see MMR sells a AN fitting that taps into the water pump boss, I thought about getting that and just capping it off. What do I do with the heater return line? Run it up front to the upper radiator hose?

 

[shurur]

I thought that line was the draw for the water pump to pull coolant from the heater core.
I don't think you can just delete it or reroute it without somehow getting a path from the heater core to that pump boss.

You can remove the hardline and run AN braided line with fittings in its place

I dont know how easy it is to access on the terminators pump boss, but the intake needed to come off on my '99. And with the intake off, it was easy just to rerun a new line through the valley again.

 

[JetmechF16]

It's hard to find any information on that line, I saw a thread by someone redoing their cooling system and he mentioned how he plugged that boss. Didn't say what he did with the line off the firewall though.

 

[hotcobra03]

I seen some info on this on another sister site.

But haven’t seen any threads on leaks being an issue.

Most of the time it’s a leaking intercooler causing coolant in valley

 

[JetmechF16]

It's not uncommon for the two o-rings to fail on the pipe that runs under the blower/intercooler, causing coolant to pool in the valley and travel down the bellhousing. Since my setup makes it pretty easy to access, I am looking to either do the AN fitting from MMR or just blocking it off on the water pump and routing heater return up front.

SlowSVT blocked off his water pump nipple and routed his heater core return line up to his crossover.

https://www.svtperformance.com/thre...-crossover-to-thermostat-housing-hose.911155/

 

[JetmechF16]

To follow-up here is what I did to eliminate the leak:

- remove stock coolant hard line in the valley
- remove stock o-ringed nipple from behind water pump
- remove heater core return hose off of fitting on firewall
- cut the sheath holding hose onto quick-connect fitting, remove hose
- reinstall q-c fitting on new 5/8 hose
- install MMR block-to-heater core fitting in boss behind water pump
- install 5/8 hose from firewall fitting to MMR nipple using 5/8 barb to 8AN adapter

This eliminates the o-ring problem.


MMR Block to Heater Core Nipple Ford Modular ALL [444903] - $34.99 : Modular Motorsports, Home of the Worlds Fastest Modular Engines

 

[*Jay*]

Yea Im pretty sure this or something in this area started happening to me right before storage, gonna get her home and on jackstands to find my slow leak. Originally thought it was my IC to reservoir hose but it was dry, that happened to me before. Thanks for the follow up, expect some PM's in April lol.

 

[roy_1031]

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