I have a 89 t2 and I replaced thermostat, got a koyo radiator,aftermarket radiator hoses. I burped the system for a LONG time and got all the air out even revd the car and squeezed the hose. Now when I went home from work I checked the hose and it was pretty freaking tight. Now I know the koyo is supposed to have higher pressure but this high did I not get out the air? Or is there something else thats wrong? And I tried the champagne test and no coolant gushing so I'm bout to be stumped..

 

The radiator cap determines system pressure.
Check the cap and the recovery system for proper operation.

The Koyo has nothing to do with it.

 

I bought it with the radiator its a koyo cap

 

It should be rated between 11 and 15 psi.

 

Wow I just looked at the package and it says 18.9 psi..but it said I needed a aftermarket cap. Should I use my other radiator cap?

 

That's too high for a rotary. Even Mazda recalled FDs that came with 1.3 bar caps back then.
Use a .9 or similar.

 

Which is about 13 psi iirc

You can get a new cap from mazdatrix.com or probably a local Mazda dealership

 

K thanks guys I have a couple laying around my garage.. lol I hope this fix my problem I'll let you guys know soon

 

Yup didn't work I'll try the other radiator cap but idk I'm getting pretty stumped what else could it be??

 

Air has to be getting in the system somehow.

 

How can I check for that

 

^This. Don't listen to whatdidusay, not that he has any good suggestions anyway. Check that your coolant overflow line isn't clogged. Go buy a new cap, they're what $5? You don't need a high performance (or high pressure) radiator cap.

Read about radiator over pressurization and defective pressure cap that may destroy radiator at Radiatorinfo.com.

 

Have you checked the pressure with a gauge? Or just felt the hose as being tight?

 

I just felt the house being super tight..and the cap I got was off my old radiator that I got from mazdatrix reading 0.9.. car has been doing this for a while even without the koyo and hoses. But I remember a hose on the firewall I had to cut shorter cause it was to right and had coolant coming out so maybe that's drawing air?

 

I've owned an Na for six years that exhibited the high pressure in the hoses as well, then my coolant system failed completely later on, could it be a clogged line going to his overflow? sure but the chances of that aren't very high.

I'm here to do what I can to help and to learn , respect that or don't even talk to me , or mention my name.

Peace

 

I haven't tried the other cap yet so I decided with why not and I have switched my other overflow hose back on which fits a lot tighter on there so I'll let you guys know tomorrow I really hope this fixes the problem

 

Also on my old engine the coolant seals went bad so I used alumaseal. Since then I haven't done a system flush now could have anything to do with it?

 

Have you actually confirmed there is a problem with your coolant system pressure with a gauge? A rad hose pressurized to 13 psi is pretty firm.

The system will only over-pressurize if it can't push coolant to the overflow. As a test, dump the contents of the overflow container and refill it with plain water. After the next drive look and see if any coolant is now mixed into the water.

 

Not yet I'm gonna do a flush then pressure test but is it possible that the water lines for the turbo might be bad

 

Is your car running hot, or are the hoses just over pressurizing, I had a bad clutch fan that made me think I had air in my system because it was running hot.

 

Its just the radiator hoses that are just over pressurized I noticed all other hoses are fine they have pressure but not to much is it cause of the koyo rad?

 

A radiator wouldn't cause more pressure to my knowledge, are any of the hoses bent in a weird way to make them fit on the new koyo?

 

Well I know I had to trim the bottom hose but its not restricting..I'm bout to say I'm gonna get every line and part in the cooling system I'm gonna buy new..lol I almost gave up on the car cause it lost power while I was pushing it and it was the intake tube by the cone wasn't tight so that came off but anyways yaa i know it has to be something simple

 

You said you checked that hose that goes to the overflow right? Easiest way is to blow through it and if it is clogged it will push out whatever is in there.

Do you have an after market temp gauge? That's one of the first things I bought for my car.

 

Ya that hose was clear I made sure and I don't have an aftermarket temp gauge