Leaking Heater

General information about the first-generation Nissan Maxima in the US. What was the Datsun 810 became the luxury leader Maxima in the US in 1981.

Moderators: plenzen, goglio704, glenlloyd, Nissan_Ranger

Post Reply
Carimbo
Posts: 459
Joined: 14 years ago

Leaking Heater

#1

Post by Carimbo » 13 years ago

Driving home tonight, unmistakable symptoms: Antifreeze oder from defroster/heater vents, stubborn fog on windows. Looked under pass. dash, saw coolant dripping good from corner of heater box. Can't tell if it is a leaking heater core, or u-hose (from firewall thru-tube to heater valve) or clamp?

FSM lists removing seats, carpet, instrument panel, radio, console, steering wheel. Evidently they built the car around the heater.

Anybody done this R/R? Any hints?

User avatar
philip
Posts: 1494
Joined: 14 years ago
Location: Southern California, USA

Re: Leaking Heater

#2

Post by philip » 13 years ago

Heater / coolant control valves are ofter the weakest link as it is a moving part having a seal. :cry:
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

Carimbo
Posts: 459
Joined: 14 years ago

Re: Leaking Heater

#3

Post by Carimbo » 13 years ago

philip wrote:Heater / coolant control valves are ofter the weakest link as it is a moving part having a seal.
Yes I know, had to rebuild one (NLA) a few years back. Still need to rip everything out, stand on head, etc.

Looks like I will disconnect the heater inlet/outlet hoses from the heater and plug them for now. Temps in the teens forecast for this week, not looking forward to no heat!

User avatar
asavage
Site Admin
Posts: 5347
Joined: 14 years ago
Location: Duvall, Wash.
Contact:

#4

Post by asavage » 13 years ago

As a temporary measure, you might try leaving the cooling system un-pressurized (ie leave the lever up on the radiator cap, if you have a lever-vent cap). That would leave you with heat, and possibly with no leak. I've done that before in a situation where it wasn't feasible to have the rig down for heater repairs right then. Corrosion is enhanced with the introduction of air, and cooling system capacity is reduced (like that's really a problem right now: my place hit 19.7°F last night), but for a week or so it might get you by.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

User avatar
philip
Posts: 1494
Joined: 14 years ago
Location: Southern California, USA

#5

Post by philip » 13 years ago

asavage wrote:SNIP my place hit 19.7°F last night),...
Brrrr. According to my digital weather station, lowest temperature here during the past week was 48° F. :wink:
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

User avatar
asavage
Site Admin
Posts: 5347
Joined: 14 years ago
Location: Duvall, Wash.
Contact:

#6

Post by asavage » 13 years ago

[OT]
It's under 16°F right now. At sea level in Puget sound, these temps aren't typical in winter; we generally stay above 20°. We are enjoying an unusually deep cold snap, following several inches of snow over the past three days. I am unable to negotiate my driveway and am parked down the road a hundred yards or so. My primary heat is propane, with portable nine-gallon ("40 lb") bottles, with a 1Kw electric space heater as backup/booster. I have four bottles, and when three are empty I haul them to town and get them refilled. That occured Saturday, I loaded the bottles Sunday and got them filled Monday, but couldn't get them home due to the driveway and about 8" of snow -- the Aero has Trak-Lok, but that just means it spins both rears instead of one, hence parking down the road.

Since home was running on the last bottle, and in this weather I have to keep the place very warm with cupboard doors open and tap open to prevent pipes freezing, and I'll burn nine gals of propane in about a week doing that, it was imperative that I get one of the filled bottles up to home and hooked up to the automatic transfer valve.

I lugged it through the snow, uphill. It's only about 60 lbs full, and it has a nice handle on it, but I am grateful that I'll be able to DRIVE up to the hookup before I have to do it again! I have obtained an age that this stuff isn't as much fun as it was back in the day.

(outside thermometer just dropped another degree)

This'll beat back the spring pest population!
[/OT]
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

Carimbo
Posts: 459
Joined: 14 years ago

#7

Post by Carimbo » 13 years ago

Pretty much gutted the front of the interior, even then the heater box was not easy to pull out. It's huge! Heater core itself is reasonable size, too bad it has to slide out from the front of the heater box which is butted up right against the firewall. Little or no thought given to serviceability there.

Pressure test showed several good leaks on the edge of the valve side end tank. Endtanks appear to be white plastic with copper clamping strap system holding them to the core.

Heater core NLA and doesn't look repairable. JY currently has one '83 so if I can get the heater core out of it in half a day I should be happy.

At least the cold cold snap is over for now; my fingers were not freezing to the tools this afternoon.

Just cleaned up for the day. Very sad to see the car like that-- no dash, seats, console, wires disconnected, etc. From the inside it looks like it's ready for the crusher. It's going to be a real challenge to get it all back together.

User avatar
kassim503
Posts: 1027
Joined: 14 years ago
Location: Stony Brook, NY

#8

Post by kassim503 » 13 years ago

Carimbo wrote:Pressure test showed several good leaks on the edge of the valve side end tank. Endtanks appear to be white plastic with copper clamping strap system holding them to the core.

Just cleaned up for the day. Very sad to see the car like that-- no dash, seats, console, wires disconnected, etc. From the inside it looks like it's ready for the crusher. It's going to be a real challenge to get it all back together.
Seats too?

So if i read this right, plastic holds coolant? Plastics from the days of old isnt that good and any plastic holding red hot coolant after 20 some years is bad news.
'83 maxima sedan, l24e, a/t, black

227K SOLD 6/7/2012

Carimbo
Posts: 459
Joined: 14 years ago

#9

Post by Carimbo » 13 years ago

kassim503 wrote:Seats too?
Yes, rear heater duct had to come out to allow the heater unit to slide out. Some of the screws are under the seats. That heater unit is BIG. Size of a small microwave oven.
So if i read this right, plastic holds coolant? Plastics from the days of old isnt that good and any plastic holding red hot coolant after 20 some years is bad news.
Plastic radiators have been in common use for years. Actually coolant should not ever be red hot. 180-190 deg. normally the hottest it should get.

User avatar
kassim503
Posts: 1027
Joined: 14 years ago
Location: Stony Brook, NY

#10

Post by kassim503 » 13 years ago

Carimbo wrote: Plastic radiators have been in common use for years. Actually coolant should not ever be red hot. 180-190 deg. normally the hottest it should get.
Only took the dash out on a few cars and I never saw a plastic rad heater core, so I guess I "ain't seen nothing yet". Ive seen newer cars have the alum/plastic radiator setup, I didnt know the heater core had that design too.

To me red hot is anything that can make me go ouch when I touch it, so coolant @ operating temp is red hot to me. Even if its nowhere near boiling over :)

Did the white plastic resemble the white plastic used on the turn signal switch on the steering column? (if you ever pulled the cover off)
Carimbo wrote: Yes, rear heater duct had to come out to allow the heater unit to slide out. Some of the screws are under the seats. That heater unit is BIG. Size of a small microwave oven.
I think this may be the one place where Nissan didn't think of serviceability when they designed it, sounds like a very very tough job.


Now would be a good time to soundproof the floor and firewall, if road noise bothers you as much as it seems to bother me.
'83 maxima sedan, l24e, a/t, black

227K SOLD 6/7/2012

User avatar
philip
Posts: 1494
Joined: 14 years ago
Location: Southern California, USA

#11

Post by philip » 13 years ago

carimbo wrote:Plastic radiators have been in common use for years. Actually coolant should not ever be red hot. 180-190 deg. normally the hottest it should get.
A plastic heater core?? :shock: I've never seen such a thing.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

Carimbo
Posts: 459
Joined: 14 years ago

#12

Post by Carimbo » 13 years ago

kassim503 wrote:Did the white plastic resemble the white plastic used on the turn signal switch on the steering column? (if you ever pulled the cover off)
Looks like discolored (yellowed) white nylon, similar to the MF switch.
philip wrote:
carimbo wrote:Plastic radiators have been in common use for years. Actually coolant should not ever be red hot. 180-190 deg. normally the hottest it should get.
A plastic heater core?? :shock: I've never seen such a thing.
Should have been more precise: Radiators w/ plastic end tanks is what I was describing. And there ARE possibilities for repair.
How To Repair Plastic Radiator Tanks But probably not successfully in this application.

User avatar
asavage
Site Admin
Posts: 5347
Joined: 14 years ago
Location: Duvall, Wash.
Contact:

#13

Post by asavage » 13 years ago

Carimbo wrote:Heater core NLA and doesn't look repairable.
Core Assy - Heater, $148 + $18 shipping, "ships in 4-10 business days" (in my experience, at least 10 days). Their site translates the Parts Catalogue part number to 27140-12F01 .

There's no way I'd put a used heater core back in, after that much work. Have you thought about having one custom made? Arctic Radiator Services in Bremerton has been flexible when I've asked; I think they'd fab one for me. Cost would be comparable or more than new though, in this case, but it'd be faster.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

Carimbo
Posts: 459
Joined: 14 years ago

#14

Post by Carimbo » 13 years ago

Al how do you find these? I called Napa, dealers, etc. No dice. When I try Nismoparts I have never been able to find anything of use in their catalog. Do you start w/ a P/N from your parts manual?

User avatar
asavage
Site Admin
Posts: 5347
Joined: 14 years ago
Location: Duvall, Wash.
Contact:

#15

Post by asavage » 13 years ago

Unfortunately, yes.

The dealer keeps telling me that a part is NLA, but nismoparts lists it. I was suspicious, but when I ordered the torque damper and it actually arrived, I became a believer. See also this thread. I looked up the part on nismoparts, then ordered it from Pinnacle to avoid the state sales tax. I don't know that I'd go back to Pinnacle again though.

Another member said that he was unable to get a harmonic balancer via nismo, but I'm not sure if I read his post correctly.

nismoparts' online parts lookup is useless (to me). It's essential to have your own Parts Catalog, and the damned things are made of unobtanium! I own one, another one came up on eBay a year ago, and that's it! I've never found another 1985 "final" one for the 910 series.

Image Image Image

I have scanned a number of FSMs over the years (Link 1, Link 2), and I can say that scanning this Parts Catalog would take a great deal of work and even more time, which I'm not in a position to donate to the cause right now. The thing is a million pages of bible paper, difficult to work with. I think I'd have to bandsaw off the binding to scan it properly.

If someone is serious about taking on that task (I estimate about 200 hours plus) I'd consider loaning it out. They'd have to prove to me that they are serious about it though, and a sample of their work.

Meanwhile, if someone needs a Nissan part number for a part they're being told is NLA, contact me. Some parts do not have accurate pictures -- Nissan provides a single clock picture that covers both analog and digital clocks, for example, and they don't show all variations of a part that the part numbers imply. Looking up heater hoses for Salvy took me an hour!

There is a 1981 Parts Catalog still available from one source -- see link in this post.

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests