questions about replace rear heat lines

[fan of fanboys]

first, before I jump into topic: what is the etiquette on this forum in regards to threads: is it preferred to create a new thread or bump and old thread? diff forums have different preferences. thanks!

ok, on to my questions. I have read several threads about replacing rear heat lines. there are a lot of diff options for what to use but I am opting for rubber hose that is rated for coolant. I live in SC so not worried about snow/salt but I do want to keep my rear heat.

1) I have seen 3/8 and 5/16 mentioned. Does it really matter what I choose? local store only has 5/16 in stock. can I use that or should I visit another store to get 3/8?

2) what length do I need? same local store only had 6' so I bought two. will that be long enough or do I need to visit another store for two 10' pieces?

going to talk this sunday. I am putting about 3/4 gallon of water in radiator every other day and avoiding longer drives because of this

 

[Twan]

I don't think that small of a size difference would be a big deal. I don't recall struggling to get the hoses on mine with the 3/8ths. 6' is probably a bit too short since you've got to go from basically the back of the passenger seat to the top of the firewall. I just bought a cheap 25' spool from Amazon and cut that down to fit.

 

[Kanoe]

If it were me I would make sure of the hose size. 3/8 hose on a 5/16 nipple is going to be difficult to seal and you are trying to fix leaks not make more, I think. I would check for you but mine is in storage for the winter. I have an inkling that it is 5/16 you need but check elsewhere to be sure.

As for your daily water fill up, you can temporarily fix that in 10 minutes if you use an 8 inch piece of hose and bypass the rear lines at the firewall. That way you don't have to stress about doing any damage to your 4runner. And you can measure the hose size while you are at it!

 

[CDNsldr]

first, before I jump into topic: what is the etiquette on this forum in regards to threads: is it preferred to create a new thread or bump and old thread? diff forums have different preferences. thanks!

ok, on to my questions. I have read several threads about replacing rear heat lines. there are a lot of diff options for what to use but I am opting for rubber hose that is rated for coolant. I live in SC so not worried about snow/salt but I do want to keep my rear heat.

1) I have seen 3/8 and 5/16 mentioned. Does it really matter what I choose? local store only has 5/16 in stock. can I use that or should I visit another store to get 3/8?

2) what length do I need? same local store only had 6' so I bought two. will that be long enough or do I need to visit another store for two 10' pieces?

going to talk this sunday. I am putting about 3/4 gallon of water in radiator every other day and avoiding longer drives because of this

I'd get the tightest fitting size. I found some oem lines in good shape at a pick and pull, so I didn't bother measuring the outer diameter.

Two 6' lengths should be plenty.

The oem lines are on the ground near the top of the photo, for reference. They're only around 4' or 5'.

 

[CDNsldr]

As for your daily water fill up, you can temporarily fix that in 10 minutes if you use an 8 inch piece of hose and bypass the rear lines at the firewall. That way you don't have to stress about doing any damage to your 4runner. And you can measure the hose size while you are at it!

Even simpler, just re-route hose A or B to the arrow.

 

[fan of fanboys]

^ I thought about something like that but Sunday is only a few days away. Not worth at this point to do a short-term fix that would just be reversed in a couple days

 

[bootheel]

5/16 will work perfect for you. Just replaced mine about a month ago. 6' length will be close to enough. Sorry I don't have an exact measurement, was feeding it off of a spool and cutting to length. If you have some old larger radiator hose laying around it would be wise to cut it up and zip tie for added protection for those new rubber hoses where they come in contact with brackets or anything that might rub a hole in them. Where they turn at the bottom of the firewall to run down the frame is one place that comes to mind.