TJ heater core bypass kit help

[Marce R]

Hi all,
The heater core is starting to leak into the cabin so want to put in a heater core bypass. I have found many kits for this but all of them are for 5/8"and 3/4" connectors but the hoses on the TJ are 5/8" and 11/16". Will the 3/4" connector by ok with the 11/16" hose. There are a couple of YouTube videos which use this type of kit and they seem to be ok. Any advice should be great.

 

[MikeE024]

Hi all,
The heater core is starting to leak into the cabin so want to put in a heater core bypass. I have found many kits for this but all of them are for 5/8"and 3/4" connectors but the hoses on the TJ are 5/8" and 11/16". Will the 3/4" connector by ok with the 11/16" hose. There are a couple of YouTube videos which use this type of kit and they seem to be ok. Any advice should be great.

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I think it would hold if sufficiently clamped.

That said, I’d consider a 180* silicone 5/8” x 5/8” hose and lube it with coolant before you slide it over the 11/16” fitting.

 

[voodooridr]

I used a 3/4-5/8 hose union on mine for 4-5 weeks while I waited for the BrassWorks core to arrive. Worked leak free, I keep the union in the Jeep just in case now

 

[Marce R]

I used a 3/4-5/8 hose union on mine for 4-5 weeks while I waited for the BrassWorks core to arrive. Worked leak free, I keep the union in the Jeep just in case now

Great! Thanks.

 

[Marce R]

I think it would hold if sufficiently clamped.

That said, I’d consider a 180* silicone 5/8” x 5/8” hose and lube it with coolant before you slide it over the 11/16” fitting.

Ok thanks. I'll have a look at it as an option.

 

[TJ4Jim]

Last time I did this, used one long turn 1/2" copper street 90, one end is 5/8 od and the other is about 3/4. couple of clamps and your good.

 

[MikeE024]

Great! Thanks.

Btw I have experience fitting both the 5/8” and 11/16” heater hose over a coolant screen’s 3/4” fittings. So I don’t fear putting a 5/8” over the 11/16” fitting.

I also don’t fear being 1/16” too loose (when properly clamped), but given the options I wouldn’t choose that route if both options are readily available and similarly priced.