Replacing the coolant storage reservoir on my 2004 Yukon became quite an ordeal. What should have taken about 20 minutes took about 6 hours, lots of which was doing internet research and driving back and forth to the parts store.
Caveat: Not only am I not a mechanic, I'm not a very good DIY guy. But there are probably lots of folks on the web in my position, so maybe this will be helpful to someone.
First, GM may no longer sell an OEM version of the coolant tank for this platform of Yukon/Tahoe/Escalade. I needed the one with the powered sensor in the bottom (which appears to be the most common version), so I got the Dorman part no. 603-102. (The OEM part no. is 19353731. Maybe you can find it. Amazon claims to have it for $89 and a 3-4 week wait.)
I ran into a problem with the Dorman tank. After replacing the tank and reinstalling the 2 coolant lines, the top return line started dribbling coolant. I tried a number of things to make it stop: repositioning the hose, repositioning the original spring clamp, and replacing the spring clamp with a worm-screw clamp, it would not stop dribbling. Did I somehow puncture the hose when I was using a pick to loosen it? I couldn't figure it out.
Finally I turned my attention to the new replacement Dorman coolant tank. I noticed two potential defects with the Dorman: first, the plastic nipple for the top hose where the leak was appeared to be oval instead of round; second, that plastic nipple had a distinct sharp-edged plastic ridge running parallel along both sides of the nipple. I believe that ridge was the problem. I think it prevented a complete seal and provided the coolant with a small path to daylight.
I drove to the parts store to inspect another Dorman tank unit --same part number. The top nipple on the second tank appeared to be round, not oval, and, more importantly, the ridge on the nipple was much less pronounced. I returned the first tank in exchange for what appeared to be the better unit.
Then, before installing the 2nd tank, I used a flat file to file down the plastic ridges on each side of the nipple. The tank now had a smooth round nipple instead of a ridged oval nipple. The hose secured to this tank with the original spring clamp did not leak. I hope the problem is solved.
A note regarding the top hose. At one point I thought the solution might be a new coolant return hose. It appears that GM no longer sells the hose, but the existing hose has the following info printed on it: 15170551 SABO Made in Brazil.
This is a custom molded hose specifically molded for this application. I could not find one in stock locally, but the inside and outside diameters appear to be the same as the 1/2 inch heater hose sold by Advance Auto.
Because of a very slightly defective replacement part, this job was a lot harder than it should have been. I hope your experience is smoother!
Edit: It's a lot easier to access the front mounting bolt if you unplug the Mass Air Flow Sensor and lift the air cleaner housing a bit. Note on removing the electrical wire to the Mass Air Flow Sensor. If your plug has the light gray plastic piece on the driver's side of the MAF, this has to be separately removed (or at least unfastened) before trying to unplug the MAF. Once you remove that gray part, you can squeeze the black tab on the plug and with reasonable effort remove the plug from the MAF. The tutorials I saw on youtube did not mention the little grey plug lock.
Caveat: Not only am I not a mechanic, I'm not a very good DIY guy. But there are probably lots of folks on the web in my position, so maybe this will be helpful to someone.
First, GM may no longer sell an OEM version of the coolant tank for this platform of Yukon/Tahoe/Escalade. I needed the one with the powered sensor in the bottom (which appears to be the most common version), so I got the Dorman part no. 603-102. (The OEM part no. is 19353731. Maybe you can find it. Amazon claims to have it for $89 and a 3-4 week wait.)
I ran into a problem with the Dorman tank. After replacing the tank and reinstalling the 2 coolant lines, the top return line started dribbling coolant. I tried a number of things to make it stop: repositioning the hose, repositioning the original spring clamp, and replacing the spring clamp with a worm-screw clamp, it would not stop dribbling. Did I somehow puncture the hose when I was using a pick to loosen it? I couldn't figure it out.
Finally I turned my attention to the new replacement Dorman coolant tank. I noticed two potential defects with the Dorman: first, the plastic nipple for the top hose where the leak was appeared to be oval instead of round; second, that plastic nipple had a distinct sharp-edged plastic ridge running parallel along both sides of the nipple. I believe that ridge was the problem. I think it prevented a complete seal and provided the coolant with a small path to daylight.
I drove to the parts store to inspect another Dorman tank unit --same part number. The top nipple on the second tank appeared to be round, not oval, and, more importantly, the ridge on the nipple was much less pronounced. I returned the first tank in exchange for what appeared to be the better unit.
Then, before installing the 2nd tank, I used a flat file to file down the plastic ridges on each side of the nipple. The tank now had a smooth round nipple instead of a ridged oval nipple. The hose secured to this tank with the original spring clamp did not leak. I hope the problem is solved.
A note regarding the top hose. At one point I thought the solution might be a new coolant return hose. It appears that GM no longer sells the hose, but the existing hose has the following info printed on it: 15170551 SABO Made in Brazil.
This is a custom molded hose specifically molded for this application. I could not find one in stock locally, but the inside and outside diameters appear to be the same as the 1/2 inch heater hose sold by Advance Auto.
Because of a very slightly defective replacement part, this job was a lot harder than it should have been. I hope your experience is smoother!
Edit: It's a lot easier to access the front mounting bolt if you unplug the Mass Air Flow Sensor and lift the air cleaner housing a bit. Note on removing the electrical wire to the Mass Air Flow Sensor. If your plug has the light gray plastic piece on the driver's side of the MAF, this has to be separately removed (or at least unfastened) before trying to unplug the MAF. Once you remove that gray part, you can squeeze the black tab on the plug and with reasonable effort remove the plug from the MAF. The tutorials I saw on youtube did not mention the little grey plug lock.
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