Coolant is dripping steadily from my rear heater lines, just below the firewall. These look like steel lines, wrapped in heavy spiral wrap. Is there a connection or rubber hose under that spiral wrap? I can see where they come out at the top rear of the engine and up the firewall to the right of the engine, no leaks there. Haynes and FSM are no help. These are hard to access, exploring is as difficult as the search function. I have to get up at 2am for a drive to O'Hare, this needs to get done pronto. Any advise? What size hose is in there?
Maybe for a temp fix until you get back you can just jump the in and out at the back of the engine where it goes to and comes from the rear heater. Probably standard 5/8 heater hose would work.
I can't see much under there, but it looks like the leak is running down from where the steel line contacts a bracket of some sort. This engine was replaced after the free first oil change went badly at the dealership. It's possible the bracket was bent then. I'm planning to replace the steel line with rubber 5/8". No green stripe or silicone available around here, so I'll make do with standard Gates for now. Think it'll hold up?
everybody seems to think that this is a PIA job (i.e. why it's called Pesky - but that's the little hose, are you talking about a different one?)
if you're in a hurry, why don't you just bypass the heater or plug the lines if that's more easily done?
E
This hose comes off a metal line at the top-rear of the engine, then runs down and across the top of the tranny under the firewall. The front heater hose comes off the same line and goes directly into the firewall. There's another metal line running down the back of the block, I believe the true Pesky resides there. I'm headed off to the shop to retrieve a very long, curved needle nose plier from my toolbox there, to loosen the clamp on the hose I'm working on.
I refuse to learn anything about the true PHH, I don't want to hear about it, I don't want to talk about it... nothing... nada... as it's quite clear that if I start thinking about it, mine will immediately start to leak....
yikes! maybe it happened already... better not go check....
E
The lines that go to the rear heater are not 5/8ths but 1/2 or 7/16ths, I can't remember. They are smaller than the front heater and all of the other hoses. I recall that on the 80's cool WJM had to have those hard lines replaced because of a similar failure. You could bypass just the rear heater but that would be a big job. The best solution is to bypass both heaters. Run a 5/8ths line from the heater control valve at the firewall to the heater return that goes to a hardpipe I believe goes into the water pump. That should take only about 15 minutes to do while consuming at #6 or 2!
It's all 5/8" at the top, haven't gotten into the hoses at the bottom. I got the top loose, but can't get my 5/8" hose pushed onto the nipple. I'll have to try again Wednesday. Bypassing all isn't good, it's still getting into the 30s here at night.
[quote author=ppc link=board=2;threadid=17154;start=msg166428#msg166428 date=1085891667]
The lines that go to the rear heater are not 5/8ths but 1/2 or 7/16ths, I can't remember. They are smaller than the front heater and all of the other hoses. Run a 5/8ths line from the heater control valve at the firewall to the heater return that goes to a hardpipe I believe goes into the water pump. That should take only about 15 minutes to do while consuming at #6 or 2!
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This is not meant to sound contrary at all so please do not take it that way, but for the purpose of perfectionism and knowledge, aren't these toyota lines metric??? I'm sure the 5/8 and such works but what I'm wondering is if the lines are metric or standard. I have a terrific European parts place close to me that sells every size metric hose you can imagine. If I knew that the line was not a 5/8 but a 12mm or whatever, and if I knew where to get that stuff, I'd rather stick to the original hose size. Anyone know the answer to this, I dont, I'm just asking. Thanks.
Know what you're saying. A few years back I spent a couple frustrating days trying to find the correct metric hose for my old 91. The the standard sizes just didn't seem to fit right and I wanted it exact. Believe it was a tranny cooler hose that had decided to leak.
[quote author=Scott M. link=board=2;threadid=17154;start=msg166484#msg166484 date=1085902557]
I got the top loose, but can't get my 5/8" hose pushed onto the nipple.
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Had this same problem once.....tracked down the metric sized hose from Toyota and the problem went away. You might also try a little of that hose lube stuff they sell at any auto parts store.
With so man foreign cars on the road, and with most US manufactures now doing things in metric sizes you would think metric stuff would be easier to find. What are standard sizes good for now a days?
my 5/8" hose is slightly larger I.D. than the bit of hose I removed from the return side of the rear system at the top of the firewall. All the metal lines up there were I think .68" O.D. with a dial caliper. I haven't looked closely at the hoses underneath, can anyone confirm those are smaller? That doesn't make sense, as they'd have to justify changing the size of the metal lines at one end ($?). I'm in Tampa at the moment, scheming of ways to fix this. Possibly soft 5/8" copper or aluminum line, insulated somehow. I'm nervous about just draping the hose over the tranny, not sure it'll hold up. My biggest problem is getting the metal 3-way piece loose from the tube going through the firewall into the front heater. If I can get that off I can get my new heater hose onto it and reinstall. Is the nipple to the front heater plastic, or something I can apply a little more force to? I soaked it with silicon before giving up, hopefully it'll come loose.
I'll plug the thing if I have to, but I use it a lot in the winter. I don't want to give the family any reasons to take the wife's truck when it's cold out.
Yes the lines to the rear heater are smaller at least on my 94, 1/2" or to be technically correct the metric equivalent. The "Y' pipes that connect front and rear heaters together have one smaller fitting brazed onto them. It makes very good sense in that the front heater and defroster require significantly more flow than the rear heater therefore the smaller pipe. The inlet and outlet of the front heater core are very fragile and will easily deform with any pressure. I bypassed the rear heater and the control valve which made the job simple. I was still able to control the temp from the dash control. May not be the best when running in combination with the A/C because the hot water would still circulate inside the heater core. Just use some long pieces of hose with big loops and you can retain the control valve. Support the hoses with some zip ties.
The two hard pipes only go part of the way to the rear heater and then there are two six inch lengths of rubber hose then more hard line to the heater. Replacement is not going to be fun of any of those pieces.
When replacing all the heater hoses at the firewall you will require three preformed hoses.
1) 5/8ths goes from hardpipe that attaches to the PHH to the control valve, 90 degree turn
2) 5/8ths goes from Y-pipe outlet of heaters to hard pipe going to thermostat/water pump, "S" shaped turns
3) 1/2 goes from rear heater hardpipe outlet to Y-pipe, 90 degree turn
One short piece of 1/2 straight section and all others are 5/8ths straight
