I wish to switch coolants and do a flush and was wondering if radiator cleaner does any damage to coolant seals or something

 

what coolant do you intend to switch to?

should be safe but you will likely need to flush the system 2-3 times in order to get most of out

Here's some reference material for you
https://www.rx7club.com/3rd-generati...lushes-977577/
Scroll down to the C: section
https://www.rx7club.com/3rd-generati...l-links-68640/

 

Im switching from g12 (previous owner had this) to fl22 ravenol. I bought like 20 liters of water in order to properly flush the coolant

 

I used prestone flush and was happy with the results. You can see my results here -- https://www.rx7club.com/build-thread.../#post12412915

 

I see! Thanks! How did you clean the plastic coolant tank on the right of the car. The overflow tank I mean

 

I am jealous that it only took you 4 flush cycles compared to what I had to endure.

Something to try:
Remove the tank and add some pebbles and your favorite detergent (simple green, bleach, Liqui Moly rad cleaner whatever) to the tank and shake it around to try and get the pebbles to agitate and scrub off any internal gunk. Do that a few times. Let it soak for a while (however many days you feel comfortable) too.
That has not worked very well for me but it helped. I wound up buying a new overflow tank. Given the age, it can't hurt to replace it before they become No Longer Available. Assuming they are still available...

 

Question is: How can I take it out?? Do I need to remove the bumper or something? I might be stupid (very actually) or just uninformed but I can't seem to figure out a way to remove it without taking out the bumper or something

 

LOL
It removes from the wheel well. Remove the wheel and fender liner and you should be able to reach it.

 

I see.. Il try that. Maybe il just shove a hose in it and fill it with some detergent and that'll clean everything out I believe

 

How do you plan on emptying it after filling it with water from a hose?

 

I also used the Prestone flush and it worked fine.

 

Just used it and it worked. Did 3 flushes and everything came out! Regarding what to use for the FD: Im curious, what I should use? Idemitsu GL-5 trans and dif fluid? Or go with GL-4 MT90 redline for trans and GL-5 for the diff (redline as well). Has anyone here used Idemitsu for transmissions and difs? (I use idemitsu as engine oil)

 

That is a topic where a lot of people have an opinion

For the trans, I've been using Redline since I like the shift feel. The MTL shifts smoother in cold weather. The MT90 takes a while to warm up and then feels similar to the MTL. I might switch to Amsoil's manual trans oil next time. Used it in my race car and it seemed to combine the good things of the MTL and MT90 - shifting smoothly when cold but a 90 weight oil.

For the diff, since it is a Torsen, use the Redline without the friction modifiers for LSD.

 

I've heard that GL-5 isn't that safe to use in the FD transmission. But then, I've saw (on essex rotary) that Idemitsu gl-5 is safe and is actually recommended and made for the exact trans. I don't want to damage anything so that's why im asking: Is it safe going with gl-5 idemitsu?

 

https://blog.amsoil.com/the-differen...d%20conditions.
Well... the difference between GL-4 and 5 are described in the above link. GL-4 is the general recommendations for manual transmissions.

Maybe Idemitsu has an additive package where 5 can work where 4 was specified. I don't know. I suppose you can give it a try. If you don't like the shift quality, you can always switch to something else. Personally, having tried various oils over the years, I'd stick to Redline or Amsoil rather than spend my time and money experimenting further. YMMV

 

I'm currently running Idemitsu in both transmission and diff. Before I had Redline MT90 and Redline diff oil. I can't state there is any difference in shifting quality. I remember right after the change, cold shifts seemed slightly better/softer with Idemitsu but it might just be the "new oil" effect.
BTW workshop manual recommends both GL-4 and GL-5

 

I believe the manual calls for GL-4 or GL-5 so I don't know why GL-5 would be unsafe.

 

Something about it eating the syncro s i believe

 

IIRC, high sulfur content in tranny or rear-end fluid reacts with and eats brass.

 

let me go straight to the usual full tard car people and oil topic conclusion and suggest that bacon grease is best

TeamPotbelly
.

 

I think I remember reading something like this on bobistheoilguy and it depends on the fluid. If it is straight GL-5 gear oil, then that was the case but the GL-5 manufactured for use in transmissions did not have the same characteristics. So that would be important to note when looking for fluid as well as researching before you buy to be sure. I ended up going with Amsoil GL4 manual tans lube in my FD. Didn't notice a difference over what was in the car from Japan honestly.

I tend to stay away from using redline unless they changed their formula, they used to use seal swellers which would ultimately lead to a lot of leaks in customer's cars that I was working on mainly with Toyotas, and Nissans. I didn't know many people with RX7's running Redline at the time so I didn't see it in those transmissions (or Mazda used a different material in their seals that wasn't affected.) I used to keep seals for transmissions in stock because of Redline fluid. Lots of clutch jobs from the front seal leaking onto the input shaft.

 

How long have you been using idemitsu for?

 

For little over 3 years, with weekend/pleasure driving. Before that I had Redline for 5-6 years.