mack123

iTrader: (4)

well it looks like mazda has one upped me again.
I recently did a restoration on an 88 turbo2 I purchased and while replacing a few vac hoses.. ones that already been replaced with cheap stuff, yet the last guy saved the old original hoses.. I came across a weird vac hose.

It looks like any other vac hose, its like 12", yet it has 3 stripes on it, white, yellow and blue. Its a factory hose.

On one end, about 1" in... it has a small metal insert, it looks like a cone, or metal valve inside the small hose.
I can blow thru one end.. its fine.. If I try the other end.. no air, its blocked..

I imagine this is for one place and one place only..
Does anyone know ? maybe hailers knows.. Ive heard he knows a lot about turbo 2's..

well, thanks all

ps. I dont mean its hooked to one of the green-white ball type check valves, this one is inside the hose, you need a light to see it..

Barwick

I'd bet a dollar says it's for the power brake booster.

mack123

iTrader: (4)

yeah the power brake booster vac line does have a white inline check valve with an arrow on it,and its a bigger hose..
this hose I wrote about is one of the smaller like 3/16 ones. I cant find any reference in any of my microfiche etc

HAILERS

If it's a small vac hose like most of them.....it's for the boost/pressure sensor. That is a orifice in line. It was meant to dampen surges to the boost/pressure sensor to prevent spikes in the boost/pressure sensor. The colored dots sound just like the ones I've seen on original equipment.

Take that hose and see if it does not reach from the bottom of the boost/pressure sensor to the vac nipple on the ACV.

You should have been able to blow thru both ways. It's just a orifice, not a checkvalve.

SureShot

You may have to trace the vac circuits that have checks, using the FSM "fuel & emissions" section.

I have a copy at the link in my sig below.
Download whatever you need.

Kenteth

that bastard is $32 from mazda. I replaced it and trasted the old one during the f5spd swap. Took two weeks to discover why I had no power breaks (Had done a complete brake swap too).

Works fine now though, was a bit irritated though.

The power brake booster hose on the driverside firewall has a check valve. If you replaced it with a straight through hose, goto mazda. :/ I hate going to them...

mack123

iTrader: (4)

thanks all.. I know, mazda parts are $$$, Ive spent several hundred on parts over the last few weeks.
Luckily I have the microfiche here at home, I can have my part numbers ready and save time.

My brake booster lines are ok, I looked it over today.
I have the factory check valves too.

Hey hailers, Ok I can blow thru both sides but one side is definately weaker.
One end has the white dot, which the factory seemed to put on hoses to mark the component end.
Would the white dot go on the ACV or Boost sensor end?
The hose is in perfect shape, Ill replace it when I know which side it goes to.
thanks all

HAILERS

The ACV end. It should be about an inch down the hose, the last time I looked. Orifice. I logged the part number on this site in an earlier post. You might search for it if need be. Use the word orifice and hailers. Some mistakenly call it a pill. That's their problem. But you could also look up pill.

mack123

iTrader: (4)

thanks hailers and all..
I will reroute the hose to the acv today.

I have the acv valve on my kitchen table, I was cleaning it, just last night, what a coincidence..

The vac hose fits perfect,exact length etc. Im happy I can take apart my acv every so often and clean all the passages,plungers etc. I want this car to outlive me.

thanks again

HAILERS

***The vac hose fits perfect,exact length etc. Im happy I can take apart my acv every so often and clean all the passages,plungers etc. I want this car to outlive me.****

The heat off the turbo bakes the relief diaphrams over time.