Subject is the question - anyone know how much fluid that rear washer tank holds? Pints, quarts, gallon? I no longer have a rear wiper, so I was thinking about re-purposing that tank for a water/meth injection system I'll eventually add to my build.

 

The US tank is pretty small, maybe 1/2 gal. I removed mine in favor of a Euro tank, and that one holds ~1.5 gal while keeping all the rear wiper function intact.

 

SBG makes a high capacity rear tank. The euro tank is larger.

 

Yeah, 1/2 a gallon is pretty small. The AEM V3 kit supplies a tank that is somewhere between 1-1/4 and 1-1/2 gallons IIRC. I knew about the larger Euro spec tanks, that sounds like it would be perfect - did they also use the Euro style tank on the Canadian market FDs? If so, it might be a little easier to get a used one. Or I suppose I could check with brother Ray and see if it's still available from Mazda and what it costs to get a new one.

I saw that too, the engineering that went into that tank is very impressive, and it's the easy button solution, but at about $450 new, it costs almost as much as the entire AEM v3 water/meth injection kit. So I think I'll try to find a Euro spec tank first.

 

Does anybody know if the JDM spec is the size of the Euro or the USDM? I was planning on doing the same thing.

 

I think the large tanks are only on cars with headlight defrosters and stuff for cold climate areas. The real deal big rear parts are IMPOSSIBLE to find used.

I also agree the stock rear tank is maybe a half gallon, it's small. The AEM tank is good but it's hard to mount and the nice thing with the SBG rear tank is it installs inside the hatch plastics so it's all hidden and doesn't eat into hatch space.

Also for what it's worth I've been using my stock front windshield washer tank for ages for windshield washing and water/meth. A whole trip to Deal's Gap with plenty of rowdy driving hasn't drained the tank fully yet. Now, doing track days where you are full throttle for a half hour is another story.

Dale

 

Hey Dale, yeah, the size & shape of the AEM tank makes it impossible to mount it anywhere under the hood in an FD. Best I can figure is to mount it to a plate that you can hang off of the rear strut bar in the rear cargo area, so it would be tucked up close to the cargo divider.

I knew you were using your front washer tank for yours, but did you manage to plumb it so you retained regular windshield washer functionality with it? I don't normally drive my FD in rainy/crappy weather, so I suppose that's a good solution, but I'd want to retain full washer functionality for the trips to DGRR when the windshield gets lots of bug splatters on all those miles of interstate.

 

The AEM tank is 1 gal I think, I still have mine from the V2 kit that I'm not using. I don't think the larger tank is available from Mazda anymore, but some Canadian model do come with them.

If you do get a large OEM tank, I found the AEM sensor to be a bit long to be install near the bottom, a VW washer tank sensor should solve that problem. The VW sensor is the same as AEM but about 1/2 the length and should fit in one of the pump port, just need to widen the port a little, and it is a push in type sensor with a gasket just like the fluid pump.

 

If anyone is interested, the current v3 AEM kit comes with a 1.15 gallon tank, tank dimensions are 10" High x 8.5" Wide x 4.25" Deep.

Thanks for the tip, that's good to know!

 

I followed instructions in this thread for using the front OEM washer tank. Mine still works fine…probably 10 years on.
https://www.rx7club.com/auxiliary-in...ite-up-883642/

I have the small rear tank and toyed with the idea of trying to ‘T’ it in to the line just upstream from the pump for additional capacity but have never really needed it.

 

Yep my OEM tank still works. My old mini mega build discusses it -

https://www.rx7club.com/build-thread...stall-1025885/

Basically I got a new windshield washer tank and put a hose coming down from the top to pull fluid and added a float to the tank. Dual purpose.

It's good to have the washer tank on a street driven car, there are scenarios where you can get stuff on the windshield that would make it dangerous to drive and a simple pull of the lever solves the problem.

Dale