Servicing Cooling System Questions

[HusseinHolland]

So as part of the general overhaul I'm replacing the leaking water pump, and the t/stat cover gasket. I wanted to remove the entire housing to give it an overall cleaning & replace the mount gasket. The issue is the long bolt feels like it's going to snap - I only tried to loosen it slightly, and it just felt wrong. If you've ever snapped a stud I think you know what I'm talking about. The question is, is that a thing that happens with these? It is a relatively long bolt, so it is possible it's twisting somewhat as it turns. I just don't want to have to remove the head to address a sheared off bolt, so if it is fairly common for these to snap, I'll leave well enough alone & just replace the cover gasket & check the T/stat.

Any input would be much appreciated

front crank seal is also obviously leaking, so I want to address that now as well

Fan blade has multiple stress cracks - Volvo used Aisin fan clutches & blades through early 90's on some models, so I have a new fan blade, just have to mod the ID to remove the 'tangs' that will be in the way

I will see if I can fit an electric fan & shroud first.  All the Volvo (Bosch) ones I have are around 3.5" depth off the rad, which is deeper than the clearance I measured. They work really well. It may work for this install as the fan is offset in the shroud. I'll experiment with that. If so, I'll add a thermoswitch in the lower hose (again using a '80's Volvo coupler intended for this purpose) as there is no rad provision for one. 

 

[Racer X]

6 minutes ago, HusseinHolland said:

So as part of the general overhaul I'm replacing the leaking water pump, and the t/stat cover gasket. I wanted to remove the entire housing to give it an overall cleaning & replace the mount gasket. The issue is the long bolt feels like it's going to snap - I only tried to loosen it slightly, and it just felt wrong. If you've ever snapped a stud I think you know what I'm talking about. The question is, is that a thing that happens with these? It is a relatively long bolt, so it is possible it's twisting somewhat as it turns. I just don't want to have to remove the head to address a sheared off bolt, so if it is fairly common for these to snap, I'll leave well enough alone & just replace the cover gasket & check the T/stat.

Any input would be much appreciated

 

 

That’s a lot of corrosion. You might be better off of you can remove the upper and lower thermostat housings together, then soak in penetrating oil. Try to remove the sending units and temp sensor first, while it is still attached to the cylinder head. After a good soak, apply some heat. I also find a sharp rap with a ball peen hammer to the bolt heads will break the rusty bond between the steel of the bolt and the aluminum of the housing.

Good luck, eh?

 

[SteveJ]

Yes, I've had those snap. No, it wasn't fun with the removal even if a friend helped me with it. No, we didn't have to drill into the head to remove the bolts, but he did have to spend a couple of hours with mapp gas to get them loose.

Having said that, I would suggest trying an induction heater on those bolts. The neat thing is that you can buy a free-form coil that you can wrap around the T-stat housing near the head to heat the bolts closer to the head. This will put the head into the bolts close enough to the head to get the desired effect.

Here's the induction heater I bought: https://www.amazon.com/gp/product/B08PD8ZSXZ

Here are the free-form coils I bought: https://www.amazon.com/gp/product/B084TCX7NG

While the price of entry may seem high, there's a pretty substantial chance this can save you from spending a couple of hours trying to remove broken bolts. 

If you want to see one of these induction heaters at work, look at my YouTube channel. I give a demonstration.

I also used this on a 280Z rear axle nut that a friend couldn't remove with a 2 foot breaker bar. I applied the heater for about 2 minutes, and I broke it loose without breaking a sweat.

[Patcon]

I agree those are easy to break. The long skinny ones in the water pump are also easy to break

[Yarb]

Looks like you might have a timing cover crank  seal leaking as well. Now is a good time to replace that as well.

[Yarb]

12 minutes ago, Yarb said:

Looks like you might have a timing cover crank  seal leaking as well. Now is a good time to replace that also.

 

[HusseinHolland]

Thanks gents.

I think I'm just going to remove the cover. I don't need to tempt fate right now. Hopefully the water pump bolts don't snap on me.

@Yarb indeed - I will be doing that as I mentioned above 🙂 Seems easier to do it whilst the rad is out the way & I can get a puller on the crank pulley.

Edited April 13, 2023 by HusseinHolland

[Racer X]

16 minutes ago, HusseinHolland said:

Thanks gents.

I think I'm just going to remove the cover. I don't need to tempt fate right now. Hopefully the water pump bolts don't snap on me.

@Yarb indeed - I will be doing that as I mentioned above 🙂 Seems easier to do it whilst the rad is out the way & I can get a puller on the crank pulley.

Good luck.

[HusseinHolland]

11 hours ago, Racer X said:

Good luck.

Is that Good luck (not likely to work out) or Good Luck (I hope you are successful in the attempt) 🤪

[Racer X]

2 hours ago, HusseinHolland said:

Is that Good luck (not likely to work out) or Good Luck (I hope you are successful in the attempt) 🤪

Good luck I hope you are successful!

 I’ve broken a lot of bolts over the years, even titanium (when I was building airplanes). When I was serving the apprenticeship to be a truck mechanic I learned how to blow a broken bolt out of the hole for an exhaust manifold on an American V8 engine using an oxy acetylene cutting torch. Of course the cylinder head was cast iron, which is something that can’t be done with bolts in an aluminum head.

And of course I’ve also been in your shoes, trying to remove steel bolts stuck in aluminum from corrosion. Not a fun time, to be sure. Even less fun when one breaks and you have to resort to left handed drill bits and “easy out” extractors.

Patience pays dividends here. So go slow, stop if you’re unsure, go have a cup of coffee or a beer, then try again.

 

 

 

[HusseinHolland]

T/stat cover came off without too much drama. I had to block sand both surfaces, they were both pitted

Chased the threads in the housing, to clean it up. There is pitting in the underside of the cover neck, but the inside is clean. I can only presume coolant has been seeping past the (crappy) Gates upper hose, that wasn't quite the right ID.

Cleaned up the pitted area with a Dremel wire wheel, I'll fill it with JB Weld

Water pump bolts didn't feel great coming out, so I worked them back & forth fair bit. Mating surface mostly cleaned up here

The original hardware for the water pump cleaned up OK, but I think I'll use newer hardware. The T/stat bolts are nasty. The Volvo bolts have integrated flanges & are higher grade

 

While I was in the bay, I added an 80's  Fiat brake line clip to replace the broken hood prop retainer (and put some primer on the area where the rad sits up against the panel

Checked the fit of the Volvo fan shroud on the rad - should work OK, the center of the fan motor will be offset to the left, and the water pump sits offset somewhat to the right. I'll test fit it once I figure out a suitable method of retaining the shroud flush to the rad core

motor..

Have to locate mating pins and/or water proof housing for the eFan connections - pretty sure they are Furukawa or Yazaki ? EDIT - Yakazi 58 Y series

EDIT - assuming the shroud & fan clear the waterpump snout, I will wire the fan same way I did on my old Volvo

Edited April 14, 2023 by HusseinHolland

[HusseinHolland]

Cleaned up around the crank, and removed the pulley & old seal. Definitely well hardened. There is a decent wear groove on the pulley seal neck, so I made sure to alter the seal depth for the new one

After that I cut down the Volvo bolts to match the Nissan length (checked that at the full length they would bottom out before pulling the pump tight to the casing)

New pump back on

Repaired T/stat cover

Volvo bolts, cut down to match Nissan original length, with 10mm heads to make it easier to access by the fuel lines, and harder to overtighten

In other news, going to add a fuel pressure gauge over here

And got a new throttle cable accordian boot. Not planning on driving it in the rain, but I don't want NY weather working it's way into the cabin

 

Edited April 15, 2023 by HusseinHolland