Hi all, been a while since I've posted here. Need some help ASAP please. I just replaced my radiator got everything back in, started to bleed the system. I noticed as I was filling up the surge tank with coolant, I can hear from time to time, fluid falling fast and hitting plastic. I didnt think anything of it at first, then it started happening again and again....I took out the air box and looked at the surge tank. The coolant is randomly leaking from the bottom of the surge tank from this orifice seen in the picture. The cap was not on the surge bc I was slowly filling up the tank as needed. So its odd this leak never happened before today...is this the pressure relief valve? While is it randomly just letting coolant fast pour from it just randomly the system is not pressurized yet well at least the tank isn't...I'm dead in the water right now, car is in the driveway till I figure this out. I called my closest deal and they have it on order, should arrive in a few hours...

 

Hi all just an update...I figured out what was happening. As I was pouring the coolant into the tank, I was pouring it towards me, and the angle I was pouring it at, was allowing coolant to flow right into the relief hole which is along the inner edge of the opening on the tank. I guess once enough coolant poured into that hole, it all came out at the bottom of the tank as it was designed to. SMH! LOL! Learned something new!

 

Posting the solutions/outcome helps us ALL !!! We've all done embarrassing sh*t !!!

 

LOL yes sir, thats the truth!

I have another issue to report, lol. So now the lower radiator hose is leaking at the radiator, no matter how tight I tighten the wormgear clamp it still leaks. This hose is only 5 years old, but I remember when the dealership replaced my radiator 5 years ago, they replaced the hoses as well b/c I requested it, since they were the original to the car (2007). After they worked on the car, the lower hose was still leaking just as it is today, so they replaced it under warranty and the 2nd new hose never leaked again.
Now today its leaking just as it did before, SMH! I'm going to try and see if I can move the clamp more towards the lip on the outlet of the radiator and see if that fixes it, but I think I may have to get an new hose, and then have to buy more coolant, bc to replace that hose will let all the coolant drain from the radiator.

 

Is the outlet to that lower hose plastic (I can't remember, installed a new radiator into a 2005 Yukon) ?? If so, be sure not to crack it.

If you feel that the new hose is OK, I might the coolant into a clean container and re-use it, and coat the outlet surface (and maybe the inside of the hose end) with Permatex Aviation then re-install the hose and see if that stops the leak.

It sounds like the hose mold may have been defective. If mine, at 5-years old for the hose, think I would just install a brand-new Gates brand hose. And return it if it leaks there.

 

Yes, its plastic. And I made sure to not overtighten it, that was my worry. So I just readjusted the position of the clamp and moved it closer to the beveled lip on the radiator outlet and re-tightened it down. Went for 2-20min test drives, and each time coolant was still leaking out. I would clean the area with brake kleen before and after each trip. So I was like F it, went to the dealer bought 2 gallons of dexcool and a new hose. And went to a diff local dealer to get the OEM rad hose clamps. I hate these wormgear clamps that the tech put on my car last time it was at the dealer 5 years ago for the radiator replacement and hose replacement. I had no idea he was going to replace the clamps with something cheaper, must have been too lazy to deal with putting the OEM clamps back on.

Anyways when I got home from the dealer, guess what? It didnt leak any new coolant?!?! WTF!? I'm so puzzled by this, why all of sudden does it just stop leaking? Maybe it needed a few warm up and cool downs to settle in to a spot where it won't leak?

Anyways I'm going to give it a few days before I return any of the stuff I bought today, just to make sure it's not going to leak anymore.

 

Personally: I don't like the factory GM clamps, tough to get off/install without special hose clamp tool (which I now have), I typically use made in USA worm drive hose clamps like this.


Anyway, here's my hose clamp story/only dealer visit story. We've had a total of five Suburbans/Yukons since 1994, all purchased used. The 2005 Yukon Denali had a sunroof which intermittently would not close (no sound, no starting to move at all) but would always open, and local ASE mechanic advised taking it to the dealer, as complicated. I tested the switch itself with ohmmeter the night before, tested fine. Using advice from local radio show mechanic, I tell GM service advisor that we will pay for a FIX, but not for GUESSING, and they agreed to that. I asked for all removed parts to be returned to us, as per radio show guy.

Dealer calls me, says it was a bad switch, and I repeat asking if this was a fix, they reply yes, $250. Get to dealer, and there's a $50 hazardous waste fee; so I ask exactly what was disposed of at all (as I had the old switch and the new box), and what was hazardous - that charge is quickly removed. Then I'm given a laundry list of recommended repairs: included in that was a quote for new radiator hoses, funny because I'd replaced the water pump a month before and had installed new Gates hoses with the stickers still on the hoses, and had used aftermarket non-GM hose clamps. My strong guess is that the hood was never even raised.

Anyway, the sunroof was not fixed, stuck in open position the very next day. The Yukon made several return trips, dealer could never fix it, and oftentimes by next day it operated fine until next outage. I fought with dealer and finally got reimbursed (was about to get credit card company to dispute the charge), and with the sunroof in closed position, I simply removed the sunroof fuse. So that's my hose clamp and dealer story.

Some years later I replaced the radiator on that Yukon (driver side plastic end cracked) and still had no leaks.

 

LOL! I'm amazed the service advisor agreed to the only pay for fix not guessing!

So to close out my story, the leak did start yet again...so I wasn't sure at that point if it was the wormgear clamp and/or the hose. So I just went ahead and bit the bullet and replaced both, wasted all that new coolant as well (didn't want to take a chance of putting contaminated coolant back into the system, being that it just rushes out of the radiator in an uncontrollable manner, splashing all over dirty parts of the engine bay and frame). Fought the OEM clamp on the lower radiator outlet, they are really hard to handle in a small space. At one point I though I screwed myself by accidentally letting the vice grips slip and the clamp on on the hose only allowing the clamp to close down much further than the space and vice grips could manage, lol. So after about 45 mins of struggling with the OEM clamp, I was able to get it situated and now no more leaks. I think the old wormgear clamp may have been the culprit, but I didnt want to waste more money on coolant and waste more time re-doing that job a 3rd time, so I just to hell with it and put a new hose as well. Still saved quite a bit of money vs having dealer do it for me, even though I had to do the job twice. lol

 

Great job !!! You did fine for not having correct hose clamp pliers, I now have a set of actual hose clamp pliers in my toolbox. Save the hose as a spare. Some folks love those spring-type clamps, claim that they give an even tightness over the entire hose circumference. Some of that type has a special "lock feature" to hold it open during assembly, which I do not like personally.


Well here's "the rest of the story": this dealer (huge dealership, Scottsdale AZ) has only one guy trained on such systems. After several return visits, the service advisor tells me "they have absolutely no idea what's wrong", claims they even talked to HQ. Well, the radio show mechanic has a large independent shop in town, and each week tells folks to notify the shop that they will pay for a fix but not for a guess, and go elsewhere if that shop doesn't agree. I asked twice and got result back that the dealer agreed; important in all this is to ask for their old/"defective" parts back and pay with a credit card, in case one has to dispute/reverse the charge on the credit card.

Anyway, while this was going on, I had posted on a GM Internet forum asking if anyone had encountered similar symptoms with a sunroof that would always open, but intermittently would not close (or even attempt to close). A GM rep contacted me through that thread and did his best to talk through with the dealer. But in the end, the dealer did end up writing me a check for the complete amount I'd paid; I don't know for sure if the GM rep facilitated this reimbursement or not. Of course the numerous trips to the dealership were "on me".

I think if the dealership had investigated the issue right when I'd brought it in with the sunroof inoperative, that they may have had a chance to diagnose; but once it sat overnight and they got around to looking at it, it worked. We ALL know the time to troubleshoot ANY intermittent is when it's NOT working, duh !!!

Any once the sunroof was closed, and I told them I expected my refund, I simply took out the sunroof fuse. Yes, when we looked at the 5-year-old Yukon and I saw a sunroof, I simply rolled my eyes as something else to go wrong. Anyway, in spring 2021 we sold that and disclosed the sunroof issue to the buyer, as we also disclosed that the windows in the rear two doors did not operate (window motors could be heard, like the mechanisms were faulty, so windows were 100% up and each secured for the near future with 2 sheet metal screws each); this is Arizona, AC is on 90% of the time, and we had only rarely more than one passenger. So with that sold we got a 2011 Yukon XL Denali in pristine condition, and Mrs, Cusser - who loves to use a sunroof - was too scared to try it (I had tried it once, was fine). In Oct. 2022 she had an accident and insurance totaled the 2011 and we picked up a pristine 2014 in November; she has yet to try the sunroof on that, but it has automatic-opening running boards that opened every time a door was opened, and we didn't care for those so I took out the fuse for that.

 

You may be able to program the running boards to stay out all the time. Or maybe that's what you did with pulling the fuse when they were out.