Urgent help needed SPF coolant leak

I keep my car in a hangar that has no electricity. The temps recently got down in the high 20s F. I went to check the car today and the area under the seats was pooled with coolant. No puddles under the car. I had no tools nor flashlight and the light was getting poor. All I could do was to soak it up with towels. I will be going out in the morning to see if I can find the source of the leak.

It seems to be coming from the tunnel low in the corners near the aft bulkhead on bith sides. I probably soaked up a quart or two. My guess is that there is a metal to flex connection there somewhere. I am looking for ideas to figure out how to approach this situation. How does the tunnel come out the top portion?

As a minimum, I need to stop the bleeding. I have no light or power out there. I guess I can get it towed, but I don't know any shop in the Medford or Grants Pass, Oregon area to tow to. I have a trailer and was working on getting the etrack in, but it is not there yet. I am rural and do not yet have a garage (just picked up plans for my new garage to be built in the next 6 months...

I was supposed to leave on a trip in two days and I will be gone for three weeks.

Thanks in advance for any guidance you can give.

Mike
 

Steve C

Steve
GT40s Supporter
Mike,

Remove the seats and the two (L&R access panels) under the main bulkhead panel.

There you will find the transition between the metal pipes that run through the center of the tunnel and connect to the rubber hoses.

I suspect that the hose clamps need tightening.
If you have never tightened them all the rubber hose clamps should have a go over.

Isn't much else there that could be a problem especially if you see no leaks anywhere else.

Steve P2125

PS: I assume you have some antifreeze in the coolant system?

PPS: I had a small leak on one of the rubber hoses there when I first got the car. After a once over on all hose clamps not a drop has lieaked since.
 
Thanks Steve, I will check that first thing!

Can it run down into the tunnel from there? How best to get it all soaked up?

Any reason to remove the top of the center console to clean it up (if it can get in there)?
 

Steve C

Steve
GT40s Supporter
Mine was just a drip that I caught in the rear section (never got into the tunnel section); you will see what is involved when you get it apart but, it could get in the tunnel section depending on ammount that has leaked and incline of the car.

Won't help to remove the top of the console as the tub iover the pipes through the tunnel is sheetmetal.

If it where I suspect probably best to raise the front of the cr and let the fluid run to the rear and soak it up there.

Steve
 

Rick Muck- Mark IV

GT40s Sponsor
Supporter
Mike,

If you want to remove the tunnel cover, I hope you have a spotweld drill 'cause it don't unbolt!

Most likely a connection at th tube to soft hose connection. Try a new clamp and do not overtighten. Many reef the clamp down so far that the hose is compressed beyond the point of the soft surface sealing and the cords inside collapse.
 
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Thanks guys, the car has antifreeze in it and has been stored this location since I got it some 5-6 years. I like the idea of raising the front. I will try that.

Mike
 
My car did the same thing when it sat outside at a car show, it quit leaking as soon as it warmed up and I was able to get it home, 100 miles.
Dave
 
Same here. I had a small leak. Fabbed up a couple of new pipes in stainless that reduced alot of the rubber hose pieces, used better clamps and no more problems.
 
Here is what I found...a few leaks due to loose clamps, one clamp too short for a location, and possibly one hose to short...shoudn't the metal tube bead be on the other side of the clamp?
 

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Jim Rosenthal

Supporter
If you can get in there to change out the clamps, you might try AWAB SS clamps, or T-bolt clamps, not tightening them down TOO much. These are marine parts, you might have to look a bit, but generally they are much better quality than SS clamps for the auto trade.
 

Steve C

Steve
GT40s Supporter
Mike,

I think like you that the bead should be well into the rubber hose and the clamp on the hose so that the bead is on the hose side of the clamp.

I believe the L&R pipes are same length.

See if the right pipe is further forward than the left where it protrudes through the front firewall and if so is there enough angle on the rubber hose that will allow it to move to the rear?

If so you might be able with 2 people (one at the front pushing and one at the rear with the clamp there loosened) push the pipe into the hose enough to properly connect it.

As far as the other clamps go: as long as you have a bitter end visable and the threads of the screw engaging the slots in the clamp you should be OK but, I agree with Jim that marinee grade clampps are better.

Suspect other than the right hose not over the pipe bead you will be OK just tightning up the others.

Steve P2125
 

Seymour Snerd

Lifetime Supporter
Here is what I found...a few leaks due to loose clamps, one clamp too short for a location, and possibly one hose to short...shoudn't the metal tube bead be on the other side of the clamp?

One thing you need to know about the aluminum pipes that run through the tunnel is that they do not have beads; they have "negative" beads. That is, the pipes are 1.75" OD with a trench machined into them with an OD of 1.65". The supplied rubber hoses and elbows are 1.75" ID.

Exacerbating this is that the pipes are a couple inches shorter than they need to be.

Needless to say this is an abolutely terrible way to configure a pipe for a clamped rubber fitting, but we're stuck with it (until we each make proper ones with real beads).

One thing I learned static-testing my cooling system at 20 psi or so is that the hose clamp must be position absolutely straight (that is perpendicular to the center line of the pipe) or it will leak no matter how hard you clamp it. The "trench" configuration also means there is a narrow range of positions along the pipe that will allow full clamping: the clamp must sit roughly centered fully "inside" the trench. But of course with the rubber hose in place covering the trench how do you tell where that range is?

IAE sealing occurs (when it does) by clamping the hose from it's natural ID down to something below it's natural ID, and then depending on the hose pressure against the outer corner of the "trench" to achieve a seal.

This is idiotic, forcing the flexibilitiy of the rubber hose to work against sealing rather than for it, and clearly not what rubber hoses and hose clamps are designed to do. If you could get 1.65" ID hose you might be able to make this scheme work, if you could get the hose over the ends of the pipe.

I don't know why SPF tries to reinvent practices that have served industry for decades, replacing them with ones that are obviously worse. What's wrong with conventional tube beading?

Also, BTW, it's only moderately difficult to pull the pipes out the front of the tunnel. So replacing them with something properly engineered is feasible.
 

Steve C

Steve
GT40s Supporter
Alan,

Is what looks like a bead in Mike's pic above really the trench? Sure appears to be a bead.

Anyway to your : "One thing I learned static-testing my cooling system at 20 psi or so is that the hose clamp must be position absolutely straight (that is perpendicular to the center line of the pipe) or it will leak no matter how hard you clamp it. The "trench" configuration also means there is a narrow range of positions along the pipe that will allow full clamping: the clamp must sit roughly centered fully "inside" the trench. But of course with the rubber hose in place covering the trench how do you tell where that range is?"

So if he moves the pipe as I suggested above (assuming he can) and clamps as you suggest he should be OK

As I noted above I had a small drip in the same area but once I tightned the clamp and now many miles later my car is dry as a bone. I annualy do a "pressure drop test" on the cooling system to insure it's OK and it is.

BTW I do NOT see the bead or trench on my pipe so Mike's hose/pipe must not be properly installed.

Steve P22125
 
Here is a close up I took through a mirror. Note the profile of the lower edge of the tube showing the trough that Alan is talking about.
 

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Seymour Snerd

Lifetime Supporter
So if he moves the pipe as I suggested above (assuming he can) and clamps as you suggest he should be OK

Yes, I think so. I'm not sure having the rear (inner edge) of the trough exposed is a problem, but I don't remember how wide the trough is. I think the key issues are:

  1. Make sure the clamp is "straight" (perpendicular to pipe centerline).
  2. Positioned correctly. I think the best position is centered in the trough. You might be able to tell where that is by feeling "through" the hose, or squeezing with a channel-lock plier to try to determine where the edges of the trough are. Or, if you have the patience, measure the position of the trough releative to a mark further down the pipe, put the hose on, and then measure to locate the center of the trough. A dangerous clamp position would be one where the edge of the clamp is near enough to, or overlapping with, the edge of the trough to form a cone-shaped clamping surface on the hose such that the clamp would tend to slip toward the center of the trough and in so doing wouldl loosen (this is one of the fundamentally terrible things about this whole idea; the only truly stable position for the clamp is exactly centered in the trough). Now that I think about it, having the hose fully cover the entire trough is the only way to have a truly stable clamp location.
Regarding shifting the pipe to get more purchase at one end or the other; you probably want the situation at the rear to determine the position of the pipes, since it is so hard to work with the clamps etc. back there.


There are some surmountable obstacles to shifting the pipes:

  1. You need to drain all the coolant. You'll still get more out as soon as you loosen the couplings on the center pipes. Might as well jack up one end and loosen the other right from the get-go so you get it all out.
  2. Friction where the pipe passes through the multi-hole sponge rubber "grommet" (for lack of a better word) at both the front and rear of the tunnel. If you doused both ends in silicone spray and twisted the pipe to help the silicone seep in, this would probably be easier. Having a helper would definitely make this easier, although I never did. Pushing the pipe to the rear will tend to push the rear grommet rearward in the tunnel, but once everything is clamped you can push it back forward where you want it by reaching into the tunnerl from the openings at the firewall with a blunt tool to stick. I don't think its position is particularly critical.
  3. The other pipes, particularly the A/C tubes, also need to be shifted relative to the grommets. I recall having to trim the ends of the aluminum A/C tubes where they are coupled to the curved ones running up above so that their ends could be closer together within their rubber coupling, thus allowing enough clamping area on that coupling forward of the forward grommet, so I could get the grommet positioned where I wanted it relative to all the pipes. I also recall the coolant bleed tube being a little bitchy about shifting within the grommets. Again, silicone spray is your friend but of course if a siliconed rubber/metal joint is allowed to rest very long the silicone loses its slippery effect. Messing with this area of the car can be quite frustrating.
 
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