Spent the last day replacing a broken coolant T. Hooked up all of the hoses and decided to pressure check the system. Plugged the coolant hose that connects to the reservoir and the pumped some air into the nipple on the reservoir that the coolant hose otherwise connects to.

Heard some dripping and narrowed it down to the back side of the larger lower coolant pipe. Note that the plastics were replaced by dealer with metal a couple years ago...

Couldn't see exactly the exact location due to the triple tube assembly. Options are leaking from the stub tube around the o-ring that seats in the rear water distributor OR slightly loose clamps at round the rubber connector.

Inasmuch as I did not have any obvious leaking between the time the coolant pipes were done and the T breaking, I can't imagine the clamps being loose. But I can still hope...

Worst case is the pressure test was too much pressure for the O-ring and it blew out of the groove.

How likely is this? (The answer to the unspoken question of how much pressure is about 3 squirts from an air compressor - guessing about 25 psi max? I put a pressure gauge on after and the leak was occurring at 15 psi...)

Also, has anyone had to pull metal coolant tubes out after install? How hard would/will it be to remove the bottom tube and/or insert? I have the triple pipe and thermostat cover off at this point having only broken the breather tube connector...

Thanks in advance for any pointers.

 

Has anyone replaced a starter after replacing the coolant tubes?

 

So my retired diesel mechanic friend said that it is extremely unlikely that a seated o-ring would fail -- even under significantly more pressure. Even less likely that a double o-ring like what is used would fail. Occam's razor is pointing to hose clamp stretch and leaks around the rubber connector tube instead. (too bad I cut that piece off just before talking to him...)

Which is good (if true), because although I was able to twist the longer portion of the lower tube vertically, it does not seem to want to actually come out without a level of force that I am uncomfortable with.

 

Lots of people.

If the coolant pipes blow, the starter gets a coolant bath. It's not unusual for the starter to fail within a few months after that happens.

For me, the starter was showing signs of age (10 years and 100k miles) with slow cranking and the occasional "turn the key and click, turn it off, try again and it cranks" thing (this is a known issue, no consensus on cause).

So I replaced it while I had everything off. 20 minutes to do it that way.

 

I am aware of having the common problem of the plastic coolant tubes blowing and a resulting starter failure. I was asking if anyone had had a starter failure several thousand miles after replacing the plastic tubes with the aluminum or that had had O-ring failure of the replacement aluminum tubes.

Basically trying to evaluate the effort (and whether there were any tricks) of removing the lower coolant tube and stub well after a cooling tube retrofit...

 

Well, there was a guy a week or so ago that had the starter go. He replaced it without pulling any of the new pipes out.

I'm not sure if that answers your question or not.

https://rennlist.com/forums/porsche-...hing-else.html

 

Yes and no. I was looking for some hints if anyone had ever removed the lower aluminum pipe after installation. I was asking about replacing the starter as it looked like the pipe had to be removed to fish it out of the V -- but, Stoney in Oz seems to have done it without removing the pipe, so that is out...

To address the leak I discovered, I am going to replace the rubber connection hose on the back side that connects the lower to the stub on the water distributor housing and cross my fingers and hope that this is where the leak came from. Planning ahead for worst case, if this does not address the leak, then I need to pull the lower pipe to replace (or reseat) O-rings.

Having pulled on the large lower end for a half hour so far, it seems frozen and there is no good place to pry against.

 

To reduce likelihood of o ring damage, clean the bores that the coolant pipes go into with 320 wet/dry. Use coolant for the wetting of the sand paper. Then use lubricant to help slide the o rings in. I used coolant for this, but there is a special lube.

 

Wisconsin Joe are you still on fb, wanted to bounce some starter questions off of you? Thanks.

 

Possibly the rubber coupler joining the metal bypass pipe to rear of engine block. Coolant gets driven by water pump to rear of engine, via this pipe.

 

Hi Dave,

This is an old post but I hope you can still provide an answer. On my car the rubber hose connected to the lower metal coolant pipe leaked so to replace it I have to remove the big lower coolant pipe from the thermostat body.. Tried many tools and hammers and pry bars to rotate it and take it out but its jammed in solid, like fused to the thermostat. I am worried if I twist it too far it might break the thermostat body which is connected to the engine.

Did you ever get the big lower coolant pipe out?