[isthenew]

Hello All,

I’ve been dealing with the AC system in my 1989 300SE with 235k miles. It was “upgraded” by the PO, though it appears they may have simply replaced the original hoses for some w/r134a attachments. As such, I have no idea what size anything is.

In any case, I’m getting ready to pull everything apart and flush my system. However, I don’t have a wrench large enough for the Low side hose in the engine compartment, next to the access valve.

My largest wrench is 7/8 inch. It doesn’t come close. I then used the largest crescent wrench I have. It almost fit. It opens to 1 1/8 inch. I’m thinking I need a 1 1/4 inch for this.

I also need another, slightly smaller wrench for the stabilizing nut. To me, that looks like a 1 inch.

These seem to be odd sizes. Are they common in the auto AC world? And am I correct in assuming they’re SAE and not metric?

To which, I’ve never used anything these sizes before. And other than this car’s AC, I don’t foresee me using them again. And they seem to be expensive (relatively), particularly when I’m not sure of the exact size.

I also don’t know the level of torque on nuts like these. My instinct is to buy a couple big crescent wrenches, and use those.

Thoughts? Ideas? Feedback?

 

[MBL87560SEC]

One of them is inch & a quarter [1-1/4].. the other is one & a sixteenth [1-1/16] in my pic.

Though the wrenches are large the tightening torque doesn't need excessive force.

Do get a rubber grommet for the A/C hoses thru firewall.. they get really tired & now's the time....

M.

 

[isthenew]

Great! Thanks! Good to know SAE and that size.

I put the crescent wrench on the smaller/stabilizing nut. It measures 1 inch. So I think I’m good with a 1 inch and 1-1/4 inch.

So here’s the next question: Would large crescent wrenches provide the torque I’ll need? Or do I need to worry about breaking them?

I’d rather buy a couple large crescents just because I’m more likely to use a giant adjustable wrench. And I can get them locally, today. I’ll need to order the others.

 

[MBL87560SEC]

Good luck...

It's pretty tight quarters there with lots going on..
Can't you negotiate a rental of those tools?

The smaller nut on the hose that comes from the expansion valve was held by an OEX34 wrench..

That's what my pic shows anyways..

 

[luckymike]

Great! Thanks! Good to know SAE and that size.

I put the crescent wrench on the smaller/stabilizing nut. It measures 1 inch. So I think I’m good with a 1 inch and 1-1/4 inch.

So here’s the next question: Would large crescent wrenches provide the torque I’ll need? Or do I need to worry about breaking them?

I’d rather buy a couple large crescents just because I’m more likely to use a giant adjustable wrench. And I can get them locally, today. I’ll need to order the others.

As long as they fit in the space available, they'll be plenty strong. Like MBL said, the torque isn't that high. Or at least it shouldn't be, and doesn't need to be.

 

[oldcarsrule1]

3rd-ed here, if you manage to damage a big adjustable wrench on that there's likely other issues!

Just a thought, since you're maybe only holding that side still, if you can get a pipe wrench in there it should work OK.

If you're worried about teeth marks you can wrap tape or cardboard around the jaws or nut

Good luck

Pete

 

[isthenew]

Thanks guys. It is tight, but i think with the air filter removed, there’s pretty good access.

I appreciate the info on the torque. I’ve seen crescent wrenches break in the past.

And I appreciate the pictures. And I was thinking on a pair of plumbers pliers or wrench. I believe there are already grooves in the nuts, so there’s no worry there.

I found a couple used wrench sets for sale locally. If any of them have the sizes, I’m gonna snag ‘em. Otherwise I’ll get those crescent wrenches.

 

[hugo2648]

@isthenew - Are you going to be replacing the condensor with a parallel flow unit? I have read they work well. A parallel flow condensor, a new expansion valve, a cleaned evaporator core and enviro-safe refrigerant seems to be the recipe to getting a great performing AC.

 

[isthenew]

I’m going to look at what all I have, flush and clean all that, and see what happens. If it still sucks, I’ll replace things.

With the “upgrade” done by the PO, I don’t know what was replaced and what wasn’t. The condenser appears to be oem. And I can’t find a parallel flow that matches how it looks to me now. So, to go that route, I think I’m looking at a DIY. Which I’ve never done. So I want to get a close look at the condenser outside the car.

And I have no idea if the compressor has been replaced or not. I looked into rebuilding those. If necessary, it seems simple enough.

Honestly, if it blows in the 50’s when driving, and at 60 when I’m stopped, and cleared the humidity, I’d be happy.

 

[hugo2648]

Plug and Play parallel flow condensers are available for W126's. See if a search brings anything up. Please post it here if you find a supplier.

 

[isthenew]

Yup. There are a couple RF condensers on eBay, but they don’t look like they match mine. ...It may be mine’s been altered.

Got me some wrenches! But while waiting on them, I decided to repair my vacuum pods. And hit a snafu. So my dash is 70% apart right now. Gotta finish that before starting the AC flush