348 Coolant Hose - OOPS!

I found a puddle of antifreeze under my 348 the other day, and after a quick search, I found that the source was the hose that runs from the bottom of the expansion tank to the fitting under the intake plenum chamber. I noticed a long time ago that it was starting to swell, but I didn't do anything about it. Well, take a look at the picture, it was ROTTEN !

Next question, can it be replaced without too much grief? Answer, YES! After removing the air filter housing and disconnecting the throttle linkage to get it out of the way, and moving a few other bits and pieces, I was able to reach under there and undo the clamp with a 1/4" drive socket. A new section of 9.5mm Gates rubber hose cost less than $3.00! The whole job only took about 90 minutes - why didn't I do it a long time ago???

I ran out of time to get the system fully bled before night fall, but I'll have it done early tomorrow.

348 owners, take a look under there and make sure your hose doesn't look like mine did!
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thanks for the info jeff !!!!

 

Nice work Jeff. You will also want to pay attention to the other hose that is under the intake. It is the one the runs from the water pump to the front of the crossover pipe. I have heard of those being over looked during the engine out major. If that one busts it is a bigtime pain in the neck to replace it with the engine in the car.

 

Had the same coolant issue after the first drive of the season, coolant all over garage floor.
I could see the expansion tank hose going to the block was leaking.
After letting the engine cool down overnight I removed the hose with just a long flat screwdriver no engine parts removal.
Order a new hose and hope I can get it reinstalled without having to remove any parts.
The coolant was pink in color and would anyone have a suggestion what kind of coolant "Brand" I should refill with.
Can different coolants be mixed ? Will the engine self bleed itself ?

Thanks everyone,
Mike
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Had the same issue after first drive of the season, coolant all over the garage floor.
I could see the expansion tank hose to the block was leaking. I let the engine cool down overnight and the next day I was able to remove the hose with just a long flat screwdriver. Order a new hose and hope that I can reinstall without having to remove any engine parts.
The coolant was pink in color, does anyone have a suggestion on what coolant I should refill "Brand" with?
Can coolants be mixed and will the system self bleed itself ?

Thank inadvance for your help,
Mike
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Sorry, duplicate post !

 

People definitely need to start checking their hoses to this fitting. This was mine during the previous removal. Minor weep but just waiting to let go I reckon.

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Then some nice chap kindly made me up a new fitting using brass.

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you can sell that !!!

 

Indeed!

 

The system will not self bleed, you will need to do that but it's a fairly easy procedure.

As for coolant, I have been using Prestone

 

Nice write-up. I took a look at mine last night and it is all swelled up as well so I will be doing this repair this summer. Did a little research and the aluminum nipple under the plenum is actually the exact same part number as the 328 and a nice stainless steel replacement is available from Hill engineering at Ricambi for 40 bucks. It's quite nice and I had to replace mine on the 328 cuz the nipple was just about corroded off! I'll have to see how it is on the 348.

 

Finally got my 9.5mm "3/8" inch coolant hose installed this morning.
Really a pretty easy fix, I just took off the four nuts on the air box and loosen the hose clamps for the sleeves that go into the suction manifold.
I then could rotate the box up enough for my son to slip the hose onto the nipple and tighten the clamp, rerouted the other end of the hose to the expansion tank.
Service the tank, started the car and put the heater on high but no warm air was coming out so decided to crack open the coolant bleeder screws.
Top one open easily but bottom one was not cooperating as it was on so tight I thought I was going to bust it off.
I just kept working the screw back and forth a little more each time until I finally got it out. Some the threads had metal in the grooves so thought I would just order new ones. They were either not available or you had to order at least $250.00 worth of parts or they would not ship, these screws are about $2.00 each.
Got a little more motivated to see if I could clean up this bleeder and maybe reuse it.
I removed the metal from the threads, clean it on my wire wheel and reinstalled it easily and then just snug up the screws, started engine and no leaks.
Now getting heat coming out the vents and could see coolant in the expansion finally going down, just need to put a little more in.
Took me longer to post this than the actual repair !

 

Well this thread got me nervous so I decided to look at mine and it was swollen and dry-rotted just like the original poster. Very easy to change and definitely a ticking time bomb. But I have to tell you I was stunned, the hose is actually completely choked off to the point where I can't even blow through it! Plus it is swollen twice the diameter of a normal hose...quite unbelievable. Now when I start the car and you remove the coolant tank cap you actually see coolant circulating rapidly where as before there was no movement whatsoever of fluid. It's just unbelievable I imagine it will probably will cool better?
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Same here, and thanks to the OP for posting as this hose is out of sight/out of mind (till now). Bought some hose on the way home , but on inspection mine was in good shape; should be good till next major in 2 years but will keep an eye on it.

 

Reviving an old thread.
Yesterday i thought the car was on fire.
White smoke with a kind of sweet smell coming from the engine bay shortly after warm up amd leaving an event.
Pulled over and found the smoke coming ftom approximately the the left bank.
No leaks under the car either.

Gauges and temps were all normal prior to and during this event.

Shut it down but was close to home so limped her home with no further smoking and no errant gauges except oil temp. It seemed kind of low.

She's sitting in garage now still with a kind of sweet smoky smell.

I haven't put her in the air yet but found this post.

Based on smell is this what you guys had? Would the coolant have run tk the front of the engine and cause a burnoff like that?

Water pump (btw) was replace ~10k miles ago with next major coming up winter this year.

TIA.

David

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