Pesky Heater Hose (PHH) and that Pesky Bottom Bolt (PBB)

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Been discussed a lot in the past, just wanted to share some new photos what to expect for those who haven't done the Pesky Heater Hose (PHH) repair yet. This is not meant to be a step-by-step how to do it thread, just a few tips and thoughts.

(If anyone wants to skip the backstory scroll ahead to the photos):

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As many people know who've done this job, if you're going to remove the PHH pipe there is a bottom bolt that is very difficult to access which is why most people just rock the pipe back and forth (after the upper and lower hoses and the upper bolt are removed) until the tab for the bottom bolt snaps off.

Then if they reinstall the PHH pipe they just leave the bottom tab unconnected or some people just do a PHH bypass with a longer section of hose and forget about the PHH pipe. I'm not saying replacing the PHH pipe is the best way compared to the bypass, it's just one way for those who want to put it back in the original configuration.

So after a lot of trial and error and busting my knuckles and brain trying to remove the PHH water pipe assembly from above or via the left front wheel well I found that the bottom PHH pipe bolt can best be accessed by first removing the valve cover then approaching from the right side of the vehicle.

Removing the valve cover means having to remove the Throttle Body and pretty much means at least loosening the heat control valve and the engine harness from the firewall. But this is not wasted effort as the heat control valve, if original, will need replacing along with the valve cover gasket and spark plug tube seals. Also the Throttle body and upper intake plenum can be cleaned up to some extent while they're off the engine including the port/tunnel for the EGR gases that can become totally blocked with carbon (not an issue if you're deleted your EGR system). It's also a good time to clean and paint/coat the valve cover if you're so inclined. So one job turns into six.

I am sure there are some people who were able to get to the bottom PHH pipe bolt via a different approach, this is just another way to go about it while at the same time taking care of a few other maintenance issues.
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The photos tell the story:

Typical appearance of a leaking PHH after a prior repair by PO. Approached the PHH at this point from the left front wheel well (vehicle on two jack stands, left front wheel and rubber curtains removed). I did not initially disconnect the transmission dipstick tube although others do for more room to work, but I later found it to be very helpful to remove the tube
and push it to one side. Removing the starter gives even more room to work.

I was unable to reach the PHH pipe lower bolt from below via the wheel well however a few others have said they were succesfull.

PHH leaking with EGR pipe in background.jpg


Old PHH was removed by using a hookbill knife along with a sharpened paring knife then long needle nose pliers to pull the pieces off the pipes.

Note in the photo below how the PHH pipe (water pipe sub assembly 87209-60381) and short pipe on the head are almost touching (hose has been removed):

PHH pipe and block pipe facing each other.jpg


Next photo below shows how the PHH pipe can be bent forward (both hoses and top bolt removed first) if doing a quickie repair ie: by sliding a new section of heater hose up onto the PHH pipe then rotating the pipe back inline then pulling the hose section down onto the other pipe. Some people report this is a bit difficult depending on how stiff the replacement hose is; soaking in hot water before installation may help.

For orientation, photo below was taken looking up from the left front wheel well, left is forward toward the radiator, right is toward the transmission (note starter has been removed lower right).

Double click on photo for close up view

PHH pipe rotated away from block pipe for quick PHH replacement.jpg



Next photo below shows the upper PHH pipe bolt with depressed hex head (hex tools like an Allen wrench cannot be used to remove this type bolt as it's a non-standard size somewhere around 7.4mm and very shallow). It's very easy to get to this bolt using a 12mm socket, 3/8" extension, and ratchet or impact wrench.

For orientation, photo taken from right side of vehicle looking down onto
the EGR pipe. Valve cover is at the bottom, out of the frame, edge of EGR valve right top corner, PHH pipe top center.

PHH pipe top bolt.jpg



Photo below is of the PHH pipe upper bolt tab (bolt removed) and the lower PHH pipe bolt to the left of the #6 injector: note faint original yellow paint on that bolt (for detail click photo twice to magnify). The valve cover is still in place in this photo.

Some people may be able to reach the lower bolt from this location with the valve cover in place but there's very little room to swing a wrench then add the risk of damaging the fuel injector.

PHH pipe top botl removed and bottom bolt.jpg
 
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More photos:

A bit out of sequence but this next photo attemps to show how cramped
the space is around the PHH pipe lower bolt when looking down from above.

In the photo follow the PHH pipe (PHH pipe on right, EGR pipe on left) down to the lower bolt (faint yellow stripe on bolt).

There's the firewall, the EGR pipe, and the PHH pipe itself all getting in the way of the lower bolt

It isn't clear from the sequence of photos, but I snapped the PHH pipe lower bolt tab first, then went back after the valve cover was removed to get to the lower PHH pipe bolt which was easy using an ICON extra long ratcheting flex head box wrench.

Point is, if you remove the valve cover first you can then remove the PHH pipe without having to snap the lower bolt tab. Then if/when replacing the PHH pipe with a new PHH attached you can reinstall the lower bolt (along with the upper) if you decide to go that route before reintalling the valve cover.

PHH pipe bottom bolt from above driver's side.jpg



This view shows the valve cover and Throttle Body removed with the heat control valve and engine harness detached from the firewall. A 10mm racheting box wrench was used to unbolt the heat contol valve from the firewall and a 12mm socket/wrench was used for the harness bracket bolts.

Both of these need to be detached from the firewall to get to the rear most valve cover bolts and also to give more room to get the valve cover up and out.

PHH pipe bottom bolt from Passenger side valve cover removed.jpg



This next photo is close up of the extra long ICON brand flex head ratcheting box wrench (the wrench was almost straight inline when I actually loosened the bolt, in the staged photos it's too close to the injector). FWIW I've found this style ratcheting wrench to be invaluable for many jobs on an 80 series.
PHH pipe bottom bolt from passenger side valve cover removed close up.jpg




I used a screwdriver stuffed into the top of the PHH pipe once I decided to snap off the tab for the bottom bolt. Took about a minute of rocking it back and forth (almost parallel to the AC pipe in the photo) before the tab snapped. Note that the EGR temp sensor connector was removed from it's mounting bracket before working in that area.

(note: this photo is out of sequence, I actually snapped the tab for the lower bolt on the PHH pipe before loosening the engine harness and heat control valve and before the valve cover was removed. Shown for reference if anyone decides to snap off the tab for the lower bolt on the PHH pipe)

PHH pipe removal by wiggling with screwdriver.jpg



Success: PHH pipe removed, note the broken off bolt tab near the bottom of the pipe:
PHH pipe removed with broken bottom tab 2.jpg


For reference, here's a photo of a new Hose/water pipe sub-assembly 87209-60381:

PHH pipe sub assembly.jpg


Trivia point: I noticed that the paint on a new pipe assembly (when I went to scuff it up to add some extra rattle can paint) was extremely thin which may explain the degree of surface rust seen on the old pipe.
 
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Reserved for photos when it's all back together (waiting on parts).
 
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Thanks for the visual reference pictures, definitely helps.

Questions:

  • Why did you opt to break off the tab when you already had access, did I miss that reason in your wright up? I’m assuming for future ease or PHH replacement.
  • What’s the Toyota technical name for the PHH?
  • Did you replace the coolant bypass hose connected to you throttle body?
 

Irish Reiver

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Thanks for the visual reference pictures, definitely helps.

Questions:
  • What’s the Toyota technical name for the PHH?
87208-60291 - Water Heater Pipe Sub Assembly is the hard pipe only. It shows as available but for x3 the price of the P/N below.

**EDIT**

87209-60381 is the number for the hard pipe with the hose already connected on one end.

Thanks @Kernal for the heads up.
 
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To our Australian member: that is fortunate your FZJ80 models do not have the EGR system. You may read that some owners in various parts of the world decide to remove their EGR systems but for some of us with annual emission inspections that's not an option.

Seems like maybe 95% of people on the forum doing this job just snap off the tab to the bottom bolt of the water pipe sub assembly (PHH pipe) because that bolt is so difficult to get to, and after multiple attempts to get to that bolt without success I went ahead and snapped the tab off like everyone else.

But then decided while I was in the mood and had the time to go ahead and replace the valve cover gasket and spark plug tube seals which were leaking along with a few other PM (preventive maintenance) items that needed attention.

And with the valve cover removed I went back to the lower bolt with the broken off tab left behind and found it was very easy to get to that bolt with the valve cover off.

So the point of the whole thread was to show people how they could avoid snapping off that bottom bolt to begin with if they planned out some common PM items ahead of time.

For example, if the heat control valve on the firewall is original or turning brown that should be replaced. And if the valve cover gasket is leaking/seeping or if your spark plug tubes are getting full of oil, those seals also need replacing. And if the PHH is leaking or looking like it might burst, that needs replacing.

And by doing all those PM items at the same time, starting with removal of the heat control valve and the valve cover, followed by the PHH water heater pipe sub assembly (87209-60281) you can actually save time and aggravation by doing them all together.

Here's the wrench I used that makes getting to that bottom PHH water pipe bolt easy once the valve cover has been removed.

ICON Flex Head Ratchet Wrench kit.jpg
 
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Seems like maybe 95% of people doing this job just snap off the tab to the bottom bolt of the pipe assembly (PHH pipe) because that bolt is so difficult to get to, and after multiple attempts to get to that bolt without success I went ahead and snapped the tab off like everyone else.

But then decided while I was in the mood and had the time to go ahead and replace the valve cover gasket and spark plug tube seals which were leaking along with a few other PM (preventive maintenance) items that needed attention.

And with the valve cover removed I went back to the lower bolt with the broken off tab left behind and found it was very easy to get to that bolt with the valve cover off.

So the point of the whole thread was to show people how they could avoid snapping off that bottom bolt to begin with if they planned out some common PM items ahead of time.

So if the heat control valve is original or turning brown that should be replaced. And if the valve cover gasket is leaking/seeping or if your spark plug tubes are getting full of oil, those need replacing. And if the PHH is leaking or looking like it might burst, that needs replacing.

And by doing all those PM items at the same time, starting with removal of the valve cover, you can actually save time and aggravation by doing them all together.

And here's the wrench that makes getting to that bottom PHH water pipe bolt easy.

View attachment 2897127
Just did my valve cover a few weeks back :( yea if I had seen this post before, it would have been changed with the tuneup
 

Irish Reiver

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Great write up @Kernal . I must admit that I employed the wiggle method when I did my first PHH job. It was also my first ever piece of maintenance on my first ever 80 so in at the deep end. The second time I did it on my next 80 I made sure I did it right and tackled the bolt. I am not a fan of the bypass method. I am not convinced that the heavy, unsupported hose is good for the heater valve. There is a reason Mr. T put a metal pipe there.
 
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A couple months ago I replaced the heat control valve on the firewall as it looked like it was about to burst. I knew the PHH needed to be replaced (but wasn't leaking yet) and also knew the valve cover gasket seeped a little bit along with the spark plug tubes, and I was about to go out of town on a long trip so figured I'd wait until summer.

But then the PHH let loose so had to dig into that, and then decided might as well fix the valve cover gasket and seals. But in doing all that I had to remove the heat control valve from the firewall all over again and busted my knuckles and wasted a lot of time trying to remove that PHH bottom bolt before removing the valve cover.

So doing all those PM's at the same time would have saved time and effort if done in this sequence:

Remove Heat Control Valve and attached hoses then unbolt the main engine harness from the firewall
Remove Valve Cover (along with Throttle body)
Remove and clean/replace EGR valve while you're in there
Remove the PHH water heater pipe sub assembly (87209-60281)

Then reassemble (with new parts/gaskets/seals) in a reverse sequence.


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An added benefit while the Throttle body and Valve cover are off you can clean up the varnish, carbon, and crud that builds up on/inside the Valve cover (and internal oil baffle), and the Throttle body butterfly, IAC port, and vacuum ports as well as the EGR tunnel in the upper intake plenum which is often completely blocked with carbon. FWIW
 
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lp2k

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i was able to drop a long ratcheting box wrench down the back (laying like Superman on top of the engine) but the damn bolt snapped when I got it to turn.
 
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Can’t find the Icon flex ratchet anymore :( I have most of the wrench sets except that one, even the webpage is no more
 
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lp2k: Glad you could get to it from above, I just couldn't, main obstacle was the EGR pipe. My guess is if the vehicle was on a lift that bottom bolt might
be reachable while standing next to the bellhousing, left side, and reaching up and forward with a long flex head ratcheting box wrench.

The top bolt on my 80 was hard to remove even after spraying with WD40 penetrating oil (tall can with flexible metal spray tube) and letting it soak. First tried a small cordless impact wrench (~100 ft lbs torque), no worky, then grabbed a mid-torque (175ft lb) cordless impact wrench and it zipped right out (could have pulled out my 3/8" ratcheting breaker bar but was lazy).

The bottom bolt also got WD-40 penetrating oil, let it soak overnight, repeat the next day, then using the extra long flex head ratcheting wrench, came right out.

calokie: here's the link to a Harbor Freight in San Jose CA that carries
the Icon wrench set:

 
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lp2k: Glad you could get to it from above, I just couldn't, main obstacle was the EGR pipe. My guess is if the vehicle was on a lift that bottom bolt might
be reachable while standing next to the bellhousing, left side, and reaching up and forward with a long flex head ratcheting box wrench.

The top bolt on my 80 was hard to remove even after spraying with WD40 penetrating oil (tall can with flexible metal spray tube) and letting it soak. First tried a small cordless impact wrench (~100 ft lbs torque), no worky, then grabbed a mid-torque (175ft lb) cordless impact wrench and it zipped right out.

The bottom bolt also got WD-40 penetrating oil, let it soak overnight, repeat the next day, then using the extra long flex head ratcheting wrench, came right out.

calokie: here's the link to a Harbor Freight in San Jose CA that carries
the Icon wrench set:

thanks,, the link was on website was dead yesterday.


So back on the topic of PHH, did you manage to change the coolant bypass hose from the throttle body to the head near the PHH? if so any tips or tool recommendations to reach the hose clamp on the head side? I must have T rex arms, I cant reach any of these hoses.
 

mdawg

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For the TB hose, I was able to use needle nose vise grips on the hose clamp after I:
  1. Removed the driver front wheel
  2. Removed the splash protector inside the wheel well.
  3. Unbolted and loosened the tranny dipstick and moved to the side a bit.
It's still a tight squeeze, though. The hardest part for me was getting a good bite on the clamp with the locking vise grips; once that was done it was pretty straightforward from there.
 
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For the TB hose, I was able to use needle nose vise grips on the hose clamp after I:
  1. Removed the driver front wheel
  2. Removed the splash protector inside the wheel well.
  3. Unbolted and loosened the tranny dipstick and moved to the side a bit.
It's still a tight squeeze, though. The hardest part for me was getting a good bite on the clamp with the locking vise grips; once that was done it was pretty straightforward from there.
Locking vice grips!! Nice thanks
 
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For the smaller diameter bypass hose, to get to the lower end at the head,
and working via the left front wheel well, another method is to use a long set of hose pliers placed around where the clamp is and pulling the hose with clamp straight off the pipe. The top end of the bypass hose is removed from the Throttle Body (TB) pipe when the TB is disconnected from the upper intake. The new hose is installed when the TB goes back on.

If you use new OEM hose clamps they come held open by a small clip
between the "ears" of the clamp which allows you to position the clamp
where you want it then flick the small clip off and you're done.

WARNING WARNING WARNING: the #2 knock sensor is very close to the bypass hose where it connects to the small pipe on the head; if you accidentally bump the knock sensor you run the risk of breaking off the top where the engine harness connector snaps on. That plastic gets extremely brittle with age and can break with the slightest hit, so some people will remove that knock sensor before starting to work in that area.
 
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