Pesky Heater Hose (PHH) et al.

[NerdNoise]

So I'm just getting around to changing out the PHH on my 80 series and while gathering my thoughts, I came to wonder what is so special about the PHH? After all, the engine compartment and undercarriage is full of rubber heater hoses. Just of the top of my head, there's the two for the rear heat, two next to the firewall, the PHH, and a few others. Should I not be changing all of these out? Am I missing something? Is it that the PHH is better fixed in the driveway than on the trail, while the others are easily accessible? If I'm doing one should I not do them all? Any estimates on total length of hose to purchase? Thanks.

 

[PACNW96]

History has shown the PHH is the most common heater/radiator hose to fail on the vehicle and has the potential to leave you stranded. It is one of if not the most difficult coolant hoses to access so if there is one hose you want to make sure is in top shape its the PHH. The fact that it is right against the block this hose is exposed to some very high temperatures unlike some of the other hoses.

Yes it does make sense to replace all your radiator/heater hoses if they have never been replaced. On my rig with just over 100k I replaced every radiator/heater hose last fall just as a precautionary measure. Definitely don't want to be swapping out hoses on the trail...

Additional resources:

index
Slee - PHH (Toyota 80 Series Land Cruiser)

 

[80t0ylc]

....I came to wonder what is so special about the PHH? After all, the engine compartment and undercarriage is full of rubber heater hoses.... Is it that the PHH is better fixed in the driveway than on the trail, while the others are easily accessible? If I'm doing one should I not do them all? Any estimates on total length of hose to purchase? Thanks.

Tell you what - take a break while you're in the middle of this project and give us your thoughts. Maybe, you can tell us if it's appropriately named or not. Might want to consider using silicone hose and constant tension clamps as some of the threads have mentioned, at least for the PHH. Yes, it makes good sense to replace other hoses while you have cooling system evacuated. As far as total length of hose to purchase - generously estimate how much you're going to need and then add about 5 feet. It's a good idea to carry some spare hose. I'd also reccommend you researching the threads and FAQs on the 80 series cooling system before you dive in to this.

Oh and welcome

 

[ALCO]

Welcome to an extremely useful site! I just replaced the PHH yesterday. My 93' just turned over 200k. I was going to use regular OE hose but after removing the old one and realizing how much of a PITA it is to get at, I quickly decided to go get some silicone hose and two of those constant torque clamps in the hopes of never, ever having to replace it again. I replaced the engine bay hoses also but still have to change the rear heater hoses by the CATS. X2 on researching the threads, there is some serious knowledge here. Long hose pliers from Harbour Freight and Sears Craftsman Item# 00947390000 Model# 28650-998 cable operated hose clamp pliers helped. Unbolt the upper transmission fill tube and move it out of the way also. Patience helps.

 

[Lugboot]

You might as well do as much as you can while you have the coolant drained. Start putting together a list after doing some searching and FAQing around. Also search for "PHH-ectomy" for another way to deal with the PHH.

Oh yeah...

Welcome!

 

[Cruiserquestions]

Welcome to an extremely useful site! I just replaced the PHH yesterday. My 93' just turned over 200k. I was going to use regular OE hose but after removing the old one and realizing how much of a PITA it is to get at, I quickly decided to go get some silicone hose and two of those constant torque clamps in the hopes of never, ever having to replace it again. I replaced the engine bay hoses also but still have to change the rear heater hoses by the CATS. X2 on researching the threads, there is some serious knowledge here. Long hose pliers from Harbour Freight and Sears Craftsman Item# 00947390000 Model# 28650-998 cable operated hose clamp pliers helped. Unbolt the upper transmission fill tube and move it out of the way also. Patience helps.

You may be the quy I am looking for. My regular garage quoted me $800.00 to replace this PHH thing. For that kind of jack, I will certainly give it a go myself. How long did it take you and did you use a manual or anything? Any other tips before I start?
Thanks

 

[ALCO]

Your time to do this will vary based on reach, hand strength, hand size. I think a long reach and small hands would help. I have a short reach and small hands. I took at least 2-4 hrs on the PHH. If you start getting ready to throw something, take a break.

Call CDAN to get the OEM hoses with bends in them. Get some decent clamps.

My main tip would be to replace the other hoses too. Remove the ones by the firewall and you can access the lower bolt holding the PHH metal tube easier. Temporarily hold the heater valve assy out of the way with a tie wrap or something. I just used the information gleaned from other posts here since I have no manual yet.

Get a long board to lay across the engine bay. I used a 2"x10"x8ft.

1. For the PHH, I found the most useful tools were:
a. needle nose vise grips.
b. cutting knife.
b. 12mm gear wrench.
c. dremel tool.
d. 1/4" finger ratchet.
e. 1/4" drive ratchet.
The sears clamp tool is pricey (~40). I found needle nose vise grips to be just as effective for the OEM clamps. You could get 2 or 3 multiple sizes of pliers for the price of the sears tool.

2. Remove both bolts holding the metal tube for the PHH.The lower one is hard to get to (use the gear wrench for this, if you can't move it with your hand, tap it with a hammer to break it loose).

3. Remove the little mud flap in the fender well (you will have to get new fasteners to put it back on, but that's the least of your worries at this point!). With a 12mm ratchet remove the trans filler tube bolts (2)and move it out of the way.

4. The outer hose clamp is the OEM wind up type. Dremel (carefully) through this and remove it. I then used the Sears hose clamp tool to open the inner clamp (by the block) and rotate it around to a more accessible position. Use the needle nose vise grips to open this clamp and move it out of the way. Cut(carefully) along the length of the hose and remove the old one. Put your new hose on the metal tube along with both clamps. Slide this onto the block nipple. Get everything into position and tighten with your finger and/or drive ratchet.

5. Burn the old PHH in sacrifice to the the Strong Land Cruiser spirits and dance three times around your truck. (Local air pollution laws may apply).

I'll try to learn to post pictures but the last time I did there were problems.

 

[80t0ylc]

One word of warning: the rear heater hoses are a different size than the other heater hoses. IIRC the front is 5/8" inch and the rear is metric, but 1/2" is close.

 

[Brian894X4]

The PHH is right next to the EGR exhaust port and is also the first hose in the heater hose system, so the coolent is the hottest and I think at the highest pressure, when making contact with this hose.

I elected to change all of my hoses when doing the PHH. As it turned it, none of the others needed to changed, but it is something I won't have to worry about, probably ever again. The only other hoses I would be particularly concerned about are the hoses that connect directly the firewall. These are extremely difficult to reach and get too and would be far easier to work in the confort of your garage or driveway rather than on the side of the road in some emergency repair.

If doing other heater hoses, I HIGHLY recommend using the Toyota OEM hoses for the formed hose sections. I suggest using Toyota hoses cut to length for the other sections as well, except the PHH, which could be whatever you want, including the silicone hose. The reason I suggest the Toyota hoses for the straight pieces is that the larger and thicker hoses are very hard to get on the connections, while the Toyota hoses are easier and are still high quality hoses.

The hoses I did not replace where the rear heat hoses and lines, which are sold as a one piece kit. The outside diameter of the rubber part of this system is the same as the other heater hoses, but has a smaller inside diameter. I think this helps to make these probably the stronger heater hoses in the system and rarely need to be replaced. However, the metal lines, part of this system are painted steel and are located directly above the cat converters. Almost every single rig out there will have the paint flaking or flaked away. If you live in dry climates or non-salt corrosive regions of the country, the lack of paint probably won't be an issue. But otherwise, these lines are likely rusted right now and will eventually spring leaks.

I have some diagrams and information on my heater hose replacement page....

ExpeditionLCMajorcoolingoverhaul

 

[retrofive]

To sum up all the all the above posts, IMO are right on the money. The PHH has its name for a reason. X2, I'd love to hear your comments in the middle of the job. I went the ectomy route due to so much cursing and breaking the OG metal pipe out .

 

[PACNW96]

BTW Brian's website was a huge help when I replaced my heater/radiator hoses. Props to you my friend...

 

[80t0ylc]

BTW Brian's website was a huge help when I replaced my heater/radiator hoses. Props to you my friend...

X2. Brian's site has a LOT of good and interesting info! Much more than just cooling system. Actually found his site before I found IH8MUD, when I was diagnosing a coolant leak which turned out to be the PHH. Some place on his site MUD was mentioned and that's how I found this wonderful site.

 

[ALCO]

Yep, I found his site while researching PHH B4 attempting my hose changes too. Thanks Brian, great info!

 

[firetruck41]

I'm sure you've seen it, but I just bought the hose and clamps from 1fzfephh.com , it was easier than searching all over town to maybe find what I was looking for. It was well worth it to me. If you haven't done the starter contacts yet, this would be a convenient time to do it, as well. Having the starter removed gets you a little more wiggle room, then you can throw in the new contacts when you put it all back together.

 

[Flyin Tyes]

might want to change the fuel filter while there.
as i remember taking it out to give me some room.
Jake

 

[Pathfinder]

The PHH is right next to the EGR exhaust port and is also the first hose in the heater hose system, so the coolent is the hottest and I think at the highest pressure, when making contact with this hose.

I elected to change all of my hoses when doing the PHH. As it turned it, none of the others needed to changed, but it is something I won't have to worry about, probably ever again. The only other hoses I would be particularly concerned about are the hoses that connect directly the firewall. These are extremely difficult to reach and get too and would be far easier to work in the confort of your garage or driveway rather than on the side of the road in some emergency repair.

If doing other heater hoses, I HIGHLY recommend using the Toyota OEM hoses for the formed hose sections. I suggest using Toyota hoses cut to length for the other sections as well, except the PHH, which could be whatever you want, including the silicone hose. The reason I suggest the Toyota hoses for the straight pieces is that the larger and thicker hoses are very hard to get on the connections, while the Toyota hoses are easier and are still high quality hoses.

The hoses I did not replace where the rear heat hoses and lines, which are sold as a one piece kit. The outside diameter of the rubber part of this system is the same as the other heater hoses, but has a smaller inside diameter. I think this helps to make these probably the stronger heater hoses in the system and rarely need to be replaced. However, the metal lines, part of this system are painted steel and are located directly above the cat converters. Almost every single rig out there will have the paint flaking or flaked away. If you live in dry climates or non-salt corrosive regions of the country, the lack of paint probably won't be an issue. But otherwise, these lines are likely rusted right now and will eventually spring leaks.

I have some diagrams and information on my heater hose replacement page....

ExpeditionLCMajorcoolingoverhaul

The website is great I am going to be using your method to replace my PHH.

 

[NerdNoise]

Great responses. Thanks. I went to CarQuest to pick up some silicone hose but they did not have any. I ended up picking up hydraulic hose (flame resistant and rated at 600psi). After reading everyone's tales, I might just drop the $20 and get the silicon online. I'll just keep the hydraulic hose as a spare. It was $0.26 per inch. I will be liberally using silicone grease though. It is one of those things that is just magic. I wrote a thread on it here. Right now, I'm just waiting for the rain to stop before I get started.

 

[tblume]

what they said.

IMHO
: the sears tool or similar is way worth it if you do other work on other cars, the PHH-ectomy makes sense to me because of the localized corrosion that happens in that particular 2" piece (there's a thread on that somewhere that I can't find now)

I did my PHH along with the radiator and I bought all the other hoses at the same time, none of them but the big hoses to and from the rad really needed replaced, but while it was drained.. you get the idea. I think the PHH part was maybe an hour of dedicated focused work during that weekend of cooling system work, the name is well deserved

and of course welcome to the 'Mud

 

[BooKilla]

The easiest way to deal with the PHH is to sell your 1FZ-FE and get a 3FE. Wham Bam Done!

 

[FJZ80AZ]

Blew a head gasket on my 93 FZJ80 so I'm refreshing everything under the hood as I tear it down and reassemble. I found a great kit to replace the PHH. It's a silicone kit and is pricey ($195) but the fit is excellent and I feel good knowing I won't have to bother with these hoses again until I'm rebuilding or replacing the motor again. Here's the kit I used http://hpsperformanceproducts.com/t...ne-radiator-pesky-heater-hose-kit-1fz-fe.html

When I finish the rebuild next week I'll post some pics... All disassembly and reassembly work done by a friend and I head work by : Rebuilt head including valves, valves adjusted w/ new shims, rebuilt and polished valve cover and intake, chromed exhaust, replaced every hose, belt, and vacuum line, rebuilt starter, alternator, and injectors, all new gaskets, new radiator, fuel filter, PCV valve, thermostat, new plugs, wires, cap & rotor. I created a spreadsheet for adjusting the valves that I can share if anyone is interested.