TLC: Pesky Heater hose

Mr. Toyota I hate you…

At first look it looked pretty easy to change out. I wasn’t sure what the guys on were talking about.


PHH – Pesky Heater Hose. A 100 mm length of 16mm (5/8 inch) straight heater hose located at the extreme LH rear corner of the 1FZ engine cylinder head. So named because it is not the easiest thing to change-out even under ideal conditions.

After 3 years of driving it finally got to me that I should really look at this. Good thing I did as it looked pretty bloated and stretched. I’ve been lucky it doesn’t look like the one on the as the ones I have seen looks corroded. It would suck even more being stuck in K country out in the cold (Kananaskis/Banff)

Here is what the hose looked like:
A little bloated and it looks like maybe a slight leak

Might explain why I lose a bit of coolant from time to time.

So, with up coming trips to the hills and trails I figure this is HIGH priority next to getting the heater to work :D

Why did I think it was easy?
o I figure I’ll just cut the hose – no biggie

Well there’s more to that than meets the eye – One has to put a new one back on  :rofl:

Dremel worked like a charm in cutting the first Cotter pin. Then I just sliced the hose so I can pull it off. The hard part was taking out the the metal clip off as it’s in an awkward position from the factory (WTF – who thought it would be such a good idea to have it facing the firewall?). Good thing I had a long angled needle nose pliers. 2 hrs later…

A lot of folks have taken off the back plate screw (there are 2 – the top one by the manifold is accessible and about 20 cm down there is a bottom screw that is IMPOSSIBLE to get to even with a flexhead wrench) that holds the PHH which, I would recommend if you can get to it. Having Asian flexible hands even I couldn’t get the back section, so I have no idea how anyone has done that.

I cut a length of silicone hose lying around in the garage (racing is a hobby) and then put some hose lube (if you don’t have any something like that use detergent soap or KY ).

So, what I ended up doing was pulling on the pipe until I cold slip one end in and then pushing it hard back in to pop it back on the engine (note lube everything).

After that I tightened everything with an 8 mm wrench and ratchet and refilled coolant.

I looked at the starter but after 4 hrs of this crap I no longer want to touch the TLC for the next few days. Peksy Heater House – you so deserve that name!

Some bad pictures of the end product.


If you’re in the US this might be the easiest way to get a hose replacement if you don’t have a hose shop near by:


Update: December 10, 2008, 03:27:04 PM

More info on next post with a few more pics on how I did the work.

From start to finish with warming the motor and waiting for some air to leave to driving around the block to make sure heat was good :)

o 4 hrs of work. Did I mention – Mr Toyota I hate you !!

Total Coolant use: 5.3 Litres

Update: December 19, 2008, 01:02:53 PM

Close up view of the bloated 18mm hose

The silicone hose I already had laying around – purchased from Green Line Hose and Fitting
o in case your wondering why I have such a hose just lying around it’s because of… race car

Make sure you buy spring hose load clamps (t-bolt clamps) or a uniform hose clamp (that is what I am using and have been switching them over in all my cars).

A couple of more shots of the hose I used. Make sure you buy from a reputable hose shop.

And just so your mind isn’t in the gutter this is what I used for lubrication for the hose
Again, a little dish detergent soap would work as well or even little WD.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.