Mark Bradley

Hi,

This is probably an easy answer for someone but I am wondering if the solenoids with part numbers B6AT-18-741 and KL01-18-741 will fit in the FD's solenoid box. There is a pretty good write-up on how to take it apart on AUSRotary (Updated 08November- Series 8 Solenoid Vacuum box &disasembly - AusRotary) but when I am looking at the images on the sites selling them the top port (C) near the plug looks like it has a cap on it. Is this cap removable revealing a nipple? Don't want to drop $400 on solenoids that don't fit.

After over a year with no boost, bad emissions and mpg it looks like the culprit is the solenoids. 1 dead, 3 not building any vac/pressure and 3 with fast leaks.

Thanks.

Mark

Mark Bradley

Not to waste anybodys time I noticed the turbo control solenoid had this cap and it was indeed removable.

DaleClark

iTrader: (55)

Yeah from what I understand the "black box" can be separated and the individual solenoids can be replaced.

Dale

Akagis_white_comet

iTrader: (4)

Correct, it can. Once I get a bit closer to finishing the FD Wiring Book, that will be put in as a bonus along with the vacuum diagram.

mikey13b

So are all of the solenoids in the box effectively exactly the same and interchangeable? Can solenoid # KL01 18741 be used for all solenoids in the box?

Mark Bradley

Yes, they are all identical. I got mine from Amayama (https://www.amayama.com/en/part/mazda/kl0118741). The box was a bit fiddly to split so use plenty of lubricants. The original how-to is useful but it skipped the part about pushing out the metal inserts. Took me a while to figure out why it was not coming apart and that was the reason. £150 cheaper than buying a whole new box so I think its worth the effort.

KYPREO

As answered on AusRotary.com, you can use KL0118741 on all solenoids. However, this guide was originally written at a time when it was hard to get genuine parts for JDM models. The part numbers listed for the guide are those that they show up on the Australian parts catalogue for Aussie delivered models, presumably because that was easier and cheaper back then. Things have changed and it is now quite easy to get parts directly from Japan. Also, Mazda Australia has had some massive price hikes and it is often twice as much to by from an Australian dealer than overseas. In other words, you may as well buy genuine parts from Japan.

The black box contains all the solenoids and check valves in it already - all new, bolt in ready to go. Part number is N3F1-20-4B0. You should be able to get this for around AUD800-850.

I also note that Mazda lists two different kinds of solenoids in the parts fiche so there must be something different about them (that said it might just be the sticker colour):

No. 1: B6AT-18-741
No. 2: FEGC-18-741

Mazda lists 3x of the No. 1 solenoid and 4x the No. 2 solenoid. They are highlighted in yellow in the diagram below. Only two of each is actually illustrated by the parts book lists the quantities required (you can see there are multiple dotted lines coming off the parts into the box showing where they go).
If you were to replace all of these individually, it would cost around $800 to replace the lot. At that price, it is better to just buy the box as a whole and you get new check valves as well!

The main exception to that is if you know for certain only a few solenoids are problematic, but in that case, the Mazda 323 part is no cheaper than the parts designated for the RX7 - all of them are around the same list price, around AUD110 each. Personally, with s8 cars being 20-25 years old now and subject to the heat of an FD engine bay, I would just get the black box with everything new and be done with it - it will last another 20 years.

billyboy

The black box itself has shown itself susceptible to not sealing when it gets old......which is one, very clutching at straws positive for the old hose, here, there and everywhere system . We've had people in the past tearing out hair when total solenoid replacement doesn't fix their issue.

Redbul

iTrader: (26)

Yeah. Buy a new box.

Redbul

iTrader: (26)

Not long ago, Powersomethingsomething on Buyee was selling about 10 boxes for $50 each. So I suppose you could buy those ten and have an unlimited supply of dodgey old solenoids.

Redbul

iTrader: (26)

Pricing has gone up about $100 and listings have become less frequent.

My guess regional dealers are reducing inventories.

https://buyee.jp/item/yahoo/auction/...ce_page_search

KYPREO

YAJ / Buyee has 10-20% surcharge on Mazda dealer prices

Mark Bradley

If that's the case over in Australia I would just replace the whole box as you suggested. I'd imagine you have a few rotary specialist who stock those kinds of things.

We don't have anyone in the UK. I think only around 240 FD's were sold because they didn't meet UK safety standards and the majority of those are either not taxed (in storage), crashed or exported from the country. Meaning everything costs an arm and a leg 😭

On the solenoid part number difference, I noticed that myself but those solenoids were also used on various other models at the time. Amayama has always been good at finding cheaper alternatives. When I did mine I could see no difference between any of the solenoids other than the filter cap which needs removed anyway. Other than they they are identical and all my issues were resolved.

mikey13b

That's good if the 2 different part numbered solenoids are indeed identical solenoids, it seems odd they have used 2 different part #s if they are identical though. I do recall it being mentioned somewhere that perhaps the difference between the 2 may be that one of them has a check valve inside whereas the other doesnt or something along those lines...

Mark Bradley

The two green/white check values protect the pressure and vacuum sides of the system as shown in the diagram. The solenoids are just redirecting the pressure/vac. They all appear to vent to atmosphere or in the case of the FPR into the manifold. I susect to protect the rest of the system if the diagrpagm in the FPR fails.

Sounds like your $20 worked. Think I paid £45 + Shipping (AUD $85) for mine. I'm pretty sure you would tell straight away if they didnt.

I also suspect they were manufactured by Mitsibushi because my turbo control solanoid port cap has the logo embossed onto it.

Redbul

iTrader: (26)

I would have guessed that the difference was that some of the rat's nest solenoids had a filter on them. If the corresponding solenoids no longer have the filter, why was the requirement dropped?

boostin13b

Maybe because they are contained in a box now rather that open and exposed?

Redbul

iTrader: (26)

I guess it is referred to as a "black box" for a reason.