Heater Core bypass - can I do it?

kharmajavah · 08-12-2008, 11:16 AM

So, as I was replacing my ruptured heater hoses, I guess I pulled too hard to get them off and now my heater core is leaking. Not badly, but enough to where I don't want to let it get too bad.

I can replace the core myself, but money is tight this month, so I'm wondering: is it safe to bypass the heater core and run a length of hose directly from the water pump to the port on the intake manifold, bypassing the heater core? Logically, it makes sense to be. But, I'm not as experienced with repair as most of you are.

I would just be bypassing the core for a couple of weeks until the next payday. does bypassing the heater core pose any problem?

Mike Romain · 08-12-2008, 11:20 AM

No problems doing a bypass except the hoses are different sizes.... If you have a good hose clamp and a nut driver or small socket wrench you might be able to get it tight enough. or use the smaller hose and grease it before trying to slip it over the nipple.

KBONSIG · 08-12-2008, 11:22 AM

What you are saying will work - I have it set up like this now for my tub swap. Runs fine - only downside I see is that if you are overheating for any reason, you can't turn on the heat.

Do yourself a solid and replace the blower moter with the 72' blazer when you replace the core.

KBONSIG · 08-12-2008, 11:24 AM

Quote:

Originally Posted by Mike Romain

No problems doing a bypass except the hoses are different sizes.... If you have a good hose clamp and a nut driver or small socket wrench you might be able to get it tight enough. or use the smaller hose and grease it before trying to slip it over the nipple.

Yes - what Mike is saying is 100% true - on the manafold I uses (2) hose clamps to keep it tight -

VACJ5 · 08-12-2008, 11:27 AM

mine is completely bypassed (via previous owner) all they did was remove the hoses from the inlet and outlet on the heater core and then clamp them to a 90 degree fitting (degree doesnt really matter) I can snap a picture later if you want...

kharmajavah · 08-12-2008, 11:27 AM

Thanks guys!

Any chance you know the hose diameters, and which goes where? Mine were incorrect when I bought it, and they've just held out until this week.

kharmajavah · 08-12-2008, 11:28 AM

Quote:

Originally Posted by VACJ5

mine is completely bypassed (via previous owner) all they did was remove the hoses from the inlet and outlet on the heater core and then clamp them to a 90 degree fitting (degree doesnt really matter) I can snap a picture later if you want...

Thanks! No need for the picture though, I understand what you mean.

Lots of quick replies today...awesome.

kharmajavah · 08-12-2008, 11:29 AM

Quote:

Originally Posted by KBONSIG

What you are saying will work - I have it set up like this now for my tub swap. Runs fine - only downside I see is that if you are overheating for any reason, you can't turn on the heat.

Do yourself a solid and replace the blower moter with the 72' blazer when you replace the core.

I've heard of the motor upgrade, but I read *somewhere* that the part numbers for the Blazer and 4.2 Jeep are now the same...so I guess they started using the same motor for replacement?

VACJ5 · 08-12-2008, 11:32 AM

cool man, very glad we could help!

Mike Romain · 08-12-2008, 11:33 AM

Quote:

Originally Posted by kharmajavah

I've heard of the motor upgrade, but I read *somewhere* that the part numbers for the Blazer and 4.2 Jeep are now the same...so I guess they started using the same motor for replacement?

Maybe for a 4.2 YJ engine or even the 4.0 engine? I also heard that 'one' parts place was using the same numbers, but don't remember 'which' one.

When in doubt, get the cheaper Blazer blower, the premium one has too long a shaft.

4lowherewego · 01-24-2011, 06:55 PM

Can someone post picture of bypassing heatercore... I got a 360 tho... should be same as 304? Or is it not a smart move?

brownbagg · 01-24-2011, 07:01 PM

you know heater cores are only $40. you could take the old one to a radiator shop and have it fix for about 25 or do it yourself, torch and solder

Andy5150 · 01-24-2011, 07:18 PM

I broke my heater core in my driveway an hour after [I] got my 360 running. I just connected the hoses together with an adapter, and its been that way for 2 yrs. and 22000 mi. I was celebrating with a few cold ones that my 360 was running great, and in a moment of genious decided that a wheelie was in order. Bad idea; heater core came in second, but the motor runs smooth and cool.

**SonicR1** · 01-24-2011, 10:06 PM

I took the one hose off because they were so long. I was able to run the front hose all the way the the back...

**nedmoore** · 01-24-2011, 10:09 PM

WOW! 457 views for a heater hose bypass!