Replacement Heater Hoses

[subzali]

Are folks just using 5/8" heater hose to replace the small diameter hoses?

Also, Is the pigtail for the rear heater supposed to wrap around the fan stator and have the plug poking out the bottom? Like in the picture below

 

[ginmtb]

Mine feeds out through the slot.

 

[78fj40mg]

Mine is like yours wires underneath the heater.

 

[FF LC FREAK]

My pigtail sticks out through the slot towards the top of the core. And yes, 5/8" heater hose all the way to the firewall.

 

[broth9640]

Hey Subzali, I have been thinking about adding a rear heater to my 1975. There seems to be bolt holes with captured nuts for it, but it didn't have one when I bought it. Trying to sort out how the heater hoses are routed and how they connect to the system. Any chance you can snap a photo and post it? Thanks.

 

[miller]

My rear heater and lines are 1/2" autozone has it bulk. That is on a 75

 

[subzali]

My rear heater and lines are 1/2" autozone has it bulk. That is on a 75

Those must be a tight fit because the copper tubing measures 0.67" OD.

 

[miller]

Not mine they are 1/2. The orginal hose was 1/2 stamped 3/75, maybe they changed it at one point?

 

[subzali]

Hey Subzali, I have been thinking about adding a rear heater to my 1975. There seems to be bolt holes with captured nuts for it, but it didn't have one when I bought it. Trying to sort out how the heater hoses are routed and how they connect to the system. Any chance you can snap a photo and post it? Thanks.

Check SSCR's restoration thread. Around page 14 there are good pics, much better than what my clapped out rig would show.

You can see the insulated copper pipes along the tranny hump here:

And a top view of the holder here:

And you have a few of them here:

There's a little plate on the firewall that protects them, shown here:

Here's another picture of the copper pipes that run along the tranny hump:

The copper pipes that run through the firewall need to have stubs pointing down for the hoses to connect to to go to a rear heater. Does yours?


To get back on topic, I wonder if the engine bay hoses are slightly bigger than the rear heater hoses. 5/8" hose barely fits on the hard pipe on the side of the engine. No way would 1/2" fit. For what it's worth the hoses I have pulled off are all original hoses so far. One is stamped sept 17 1976 but no size is indicated.

 

[Weber Sarge]

I had the same issue with my old Samurai - the heater hoses were actually 9/16" and they do exist . There is a metric version , can't remember the size right now ....
Sarge

 

[Jimbo 7140]

Since I just searched for and found my brass T fittings in preparation of adding my rear heater, I checked the T fitting pipe diameters. The main pipe is 0.67 inch diameter for the lines between the engine and the front heater. The pipes to and from the rear heater is 0.55 inch diameter. I don't know if they are year specific, but the T fittings show up fairly on eBay. So does the oval firewall grommet with two holes the fittings pass through. Good luck.

 

[subzali]

Since I just searched for and found my brass T fittings in preparation of adding my rear heater, I checked the T fitting pipe diameters. The main pipe is 0.67 inch diameter for the lines between the engine and the front heater. The pipes to and from the rear heater is 0.55 inch diameter. I don't know if they are year specific, but the T fittings show up fairly on eBay. So does the oval firewall grommet with two holes the fittings pass through. Good luck.

I went out and took a bunch of measurements last night, very interesting stuff and confirms what you provided. I converted the measurements to mm because I'm sure that's what Toyota used.

Heater supply and return pipes (from the block): 17mm OD
Front heater connection pipes: 17mm OD
Heater supply and return hose: 17mm ID, 25mm OD (4mm thickness)
Branch pipes to rear heater: 14mm OD
Rear heater connection pipes: 14mm OD
Rear heater supply and return hose: 14mm ID, 22mm OD (4mm thickness) - I noted these were the original hoses, stamped "WATER HOSE 76 09 17 S"

 

[subzali]

Has anyone tried to see if Toyota has bulk coolant hose like they have the bulk vacuum hose? The 5/8" hose is way too tight on my engine bay piping and is too loose on my rear heater connection.

 

[subzali]

After some back and forth with the dealer regarding discontinued part numbers etc. I have found a solution. Oh and by the way these are surprisingly inexpensive, more than bulk 5/8" but a lot better solution IMO.

This applies to a 77 FJ40 with rear heater, YMMV.

1. Starting with the supply hose coming off the top of the head going to the heater control valve, I found 5/8" to be way too tight on these fittings. The original part number is 99552-30520, and it is 520mm long (ref. the ‘520’ in the part number). It is superseded by 99556-31000, which is 1000mm long (ref. the '1000' in the part number). No problem, we have the technology to trim it. The ID measures at about 16mm, so it will be a snug fit over the 17mm fittings. It has an OD of about 23mm, so the wall thickness is about 3-3.5mm.

2. The next guy is the supply hose coming off the bottom of the heater control valve going to the pipe into the cabin, the original part number is 99552-30050. It is 50mm long, 16mm ID, but NLA with no supersession. But we have plenty of leftover from our previous trim job so it’s no problem to make it.

3. The next connections are connected on the stubs going to/from the front heater core. The original part number is 99552-30075 and they are 75mm long, 16mm ID. They are superseded by 99556-30100, which are 100mm long. Again, trimmed to proper length and fit right up.

4. On the return back to the cooling system, the first hose goes from the firewall and connects to the pipe on the side of the block. There were two part numbers for this one, not sure why, and 99552-30280 (280mm long, 16mm ID) is no longer available. 99552-30260 (260mm long, 16mm ID) supersedes into 99556-30300 (300mm long). I trimmed it to 260mm (280mm was too long) and fitted it into place.

5. The last one on the return, going between the block and the fitting on the radiator outlet hoses, originally had a part number of 99552-30320 with a length of 320mm, 16mm ID. It was superseded by 99556-30500 (500mm length, 16mm ID). Trimmed a bit off of this one and connected it up. In hindsight I could have just bought a 99556-31000 and could’ve gotten #1 and #5 out of the one hose.

6. For the rear heater circuit, this has the smaller diameter hoses, and this is where the OEM hose is great because the small hose clamps really do not fit well over 5/8" heater hose in this instance. Starting with the short stub hoses coming off the pipe near the firewall (there are two of them), the original part number is 99552-20085 (85mm long, 13mm ID) and is no longer available with no supersession. That is okay because I will have some extra below.

7. For the two long hoses running at the back of the tranny hump along the floor, the original part number is 99552-20580 and is 580mm long. It is now 99556-20700 and is 700mm long, 13mm ID. I trimmed them to length. The new hose has a 13mm ID and 21mm OD so it is a snug fit over the 14mm pipe connections and has about 4mm wall thickness.

This picture shows the new hose on the bottom and how much longer it is than the hoses it needs to replace, hence the trimming required:

In conclusion, here are all the hoses you need to do the replacement:

1x99556-31000 ('1000' = 1000mm length, 16mm ID). You will cut this into one 520mm, one 320mm, and one 50mm length to do hoses #1, #2, and #5.
2x99556-30100 ('100' = 100mm length, 16mm ID). You will trim each of these down to 75mm for hose #3.
1x99556-30300 ('300' = 300mm length, 16mm ID). You will trim this down to 260mm (verify that 280mm is too long first) for hose #4.
2x99556-20700 ('700' = 700mm length, 13mm ID). You will trim each of these down to one 580mm and one 85mm for hoses #6 and #7.



OFF-TOPIC EDIT:
99556-20800, 20900, 21000, 21250, 21450, and 21850 are found on Hiace, Townace, Liteace, and Toyoace trucks. These would be hoses 13mm ID and 800, 900, 1000, 1250, 1450, and 1850mm in length, respectively. Not available for the US market.

 

[ginmtb]

After some back and forth with the dealer regarding discontinued part numbers etc. I have found a solution. Oh and by the way these are surprisingly inexpensive, more than bulk 5/8" but a lot better solution IMO.

In conclusion, here are all the hoses you need to do the replacement:

1x99556-31000. You will cut this into one 520mm, one 320mm, and one 50mm length to do hoses #1, #2, and #5.
2x99556-30100. You will trim each of these down to 75mm for hose #3.
1x99556-30300. You will trim this down to 260mm (verify that 280mm is too long first) for hose #4.
2x99556-20700. You will trim each of these down to one 580mm and one 85mm for hoses #6 and #7.

Thank you so much for posting this - I'm getting ready to replace all the rubber hoses and did not have this stuff figured out. Will add to my order!

 

[Weber Sarge]

Great info , thanks ...
Sarge

 

[Chungas Revenge]

Much obliged!

 

[antFJ]

Silly question but what color are the hoses? It would be cool to find the original red hoses.

They are red on my 1971

 

[subzali]

They are black.

 

[Nottajeep]

Excellent Info!
FAQ Material

After some back and forth with the dealer regarding discontinued part numbers etc. I have found a solution. Oh and by the way these are surprisingly inexpensive, more than bulk 5/8" but a lot better solution IMO.

This applies to a 77 FJ40 with rear heater, YMMV.

1. Starting with the supply hose coming off the top of the head going to the heater control valve, I found 5/8" to be way too tight on these fittings. The original part number is 99552-30520, and it is 520mm long (ref. the ‘520’ in the part number). It is superseded by 99556-31000, which is 1000mm long (ref. the '1000' in the part number). No problem, we have the technology to trim it. The ID measures at about 16mm, so it will be a snug fit over the 17mm fittings. It has an OD of about 23mm, so the wall thickness is about 3-3.5mm.

2. The next guy is the supply hose coming off the bottom of the heater control valve going to the pipe into the cabin, the original part number is 99552-30050. It is 50mm long but NLA with no supersession. But we have plenty of leftover from our previous trim job so it’s no problem to make it.

3. The next connections are connected on the stubs going to/from the front heater core. The original part number is 99552-30075 and they are 75mm long. They are superseded by 99556-30100, which are 100mm long. Again, trimmed to proper length and fit right up.

4. On the return back to the cooling system, the first hose goes from the firewall and connects to the pipe on the side of the block. There were two part numbers for this one, not sure why, and 99552-30280 (280mm long) is no longer available. 99552-30260 (260mm long) supersedes into 99556-30300 (300mm long). I trimmed it to 260mm (280mm was too long) and fitted it into place.

5. The last one on the return, going between the block and the fitting on the radiator outlet hoses, originally had a part number of 99552-30320 with a length of 320mm. It was superseded by 99556-30500 (500mm length). Trimmed a bit off of this one and connected it up. In hindsight I could have just bought a 99556-31000 and could’ve gotten #1 and #5 out of the one hose.

6. For the rear heater circuit, this has the smaller diameter hoses, and this is where the OEM hose is great because the small hose clamps really do not fit well over 5/8" heater hose in this instance. Starting with the short stub hoses coming off the pipe near the firewall (there are two of them), the original part number is 99552-20085 (85mm long) and is no longer available with no supersession. That is okay because I will have some extra below.

7. For the two long hoses running at the back of the tranny hump along the floor, the original part number is 99552-20580 and is 580mm long. It is now 99556-20700 and is 700mm long. I trimmed them to length. The new hose has a 13mm ID and 21mm OD so it is a snug fit over the 14mm pipe connections and has about 4mm wall thickness.

This picture shows the new hose on the bottom and how much longer it is than the hoses it needs to replace, hence the trimming required:

In conclusion, here are all the hoses you need to do the replacement:

1x99556-31000 ('1000' = 1000mm length). You will cut this into one 520mm, one 320mm, and one 50mm length to do hoses #1, #2, and #5.
2x99556-30100 ('100' = 1000mm length). You will trim each of these down to 75mm for hose #3.
1x99556-30300 ('300' = 300mm length). You will trim this down to 260mm (verify that 280mm is too long first) for hose #4.
2x99556-20700 ('700' = 700mm length). You will trim each of these down to one 580mm and one 85mm for hoses #6 and #7.