I bought that adjustable vacuume modulator (AVM) and thought just putting that on and adjusting would be the end of it but no this is what happened.

1. put car on ramps and took of the vacuume lines to the original vacuume modulator (OVM) then had to clean what looked like 30 years of crap of the side of the box (that took a while) then i cleaned it again cause i didnt want any dirt to get into the box , started to remove the OVM with multigrips when it was nelly all the way out i got the AVM ready in the other hand (as to not loose too much fluid cause im broke) tried to quickly replace the OVM with the AVM but it was just one of those days lost about a litre of oil but the AVM went in sweet. Hook every thing back up

Test 1 started driving to warm the car up to check the fluid started off in D and took off like normal till 30k's and it felt like the tranny brakes were locking and only just made it to 40k's and still wouldnt shift, got to the flat spot in the road checked the level of fluid in the tranny its right on low so i roll it down the hill home and on the ramps and

2 I go up to the shops to try and get some fluid (angry now cause it should work with the fluid low but maybe not im hoping) get to the shops and they are closed so i go to a servo on the way home then I dont have enough for the 5L of fluid at the servo so i go home (this is in mums car by the way) get home realize there was a one litre at the servo, so I walk back up th servo and theres just enough in the account to get it so i did.
I got back to the car and warmed it up again ran it through the gears then put about 100ml of fluid in and checked it and it said it was full but i seen about 1L come out so i was confused i knew more fluid had to go in so i put more fluid about 300ml more and checked again it was just above full the same as before any way put like 100mls at a time till there was 800mls in there and it still said the same thing a bit over full so

Test 2 i test drove it again and the same thing as befor gets to 30k's and brakes in D but manual shifts alright (but not well) in 1 and 2.
I get to the flat spot up the road and run it through all the gears check the level and its way too high so

3 I get home let it cool off, (which takes ages autos get pretty hot) start taking the vacuume line off and then let some oil out of the tranny bout 200ml cause thats how much i got left. while im there i adjust the AVM 2 turns out.

Test 3 much the same as the others. Level in the tranny is still too high.

4 Cool car down (ages again)
let a bit more oil out
adjust AVM 1more turn out

Test 4 much the same and oil level too high.

5 cool car (is now dark and the next day )
drop abit more oil
adjust AVM 1 more turn out (this is as far as i would like to take it as it can be damaged from winding out too far)

test 5 car dosnt start no crankin nothing (angry now already first thing in the morning on day 2)
So i think its the inhibitor switch so i dis connect that properly using the manual to find the wires get in the car and nothing (more angry)
I get the multi meter and check the battery its fine
I get a wooden base ball bat and gentely persuade the starter to start and he is scared of me cause im pretty angry now and every things fixed car starts and i warm it up and drive it its a bit better but still does that breaking thing.
But now if i drive in D till 40k;s pullit to 2 and it spins 2nd's thought that was pretty cool.
oil level was about 1cm past full

6 let car cool (not long enough)
burned myself when draining fluid lost a fair bit
put back togeather with the AVM still in.

test 6 drove a bit better (seccond cherpys a bit better too)
Still has the brakeing in D which sucked couldnt get 3rd gear still either.

Oil level was pretty much spot on

7 was gettin late and i had to work the next day so i wanted to put the OVM back on so i could get to work
Put the OVM on
warmed up the car topped the fluid up again and now it works better than it ever has no strong thuds or clangs just nice changes and even third too

So I learned that when u top up auto fluid each time u put some in you have to run it through the gears and test it in P thats how I accidentaly over filled it.

So all i actually did was clean it (the box) lose a bit of fluid put the AVM on put some fluid in drain some out adjust the AVM take it off and put the OVM on so tecinally i did nothing but it WAS 2 DAYS OF VERRY FRUSTERATING NOTHING LOL but its all good in the end.

Thats the full story I promise
Thanks again everyone.

Can you tell us what you did to fix it. Or is it one of those things where you dont know what you did but it works now
Well done

After alot of muckung round it finaly works now and better than it ever did!

Cheers fellas

Thought that might be the case with the alternater pump thingy. Cheers for cleerin that Dodge.

I will tap in a seccond line if the adjustable modulator dosnt work or with a washer as well as this is easier than pullin the manifold off and that.

Cheers everyone for the info especially dodgeman just got to get round to puttin words into action will let u know if theres any dramas.

Quote:This won't fix anything, it will create a problem instead as the vacuum output has no relationship to engine load,... road speed, or the throttle setting.
If you go back 15 posts from here you can get some idea why.
If you had the faintest idea how these things work you wouldn't make such ill informed suggestions. Sorry to be a bit harsh, but better informed suggestions will cost the end user of it a lot less money & grief.

The Vacuum pump on the altenator is often used on Diesel engines to provide Vacuum for the brake booster.

I would try something along the lines of what has been said; Take off the manifold and tap each manifold runner and then use standard pipe and fitting from a plumbing or hose/fitting shop and bridge them. Have an output to the transmission line somewhere on that bridge tube. Easy and should be less then $20 in parts. Be sure to have the manifold cleaned out very well after the tapping, you don't want any metal flakes from the manifold going into the engine.

Cheers MLS will try this if there is not enough adjustment on the adjustable one (already bought it today so I may aswell use it)

Kegs with this navara vacuum pump does it create vacuume at idol and no vacuume at W.O.T. cause if it creates vacume all the time and more vacuume at more revs then I dont think it would work because i was looking on e bay and seen vacume pumps for cars some for like $5 and those vacuume canister things but I dont think it would work.

what does the vacuum pump actualy do on a navara (ie what does it create vacuume for)?


Also started reading about the autos in the 120y book and autos are a work of art very complex in opperation still would rather a manual any day though.

just go get a alternator off a nissan navara with a vacuum pump and chuck it on should fix the problem.

Something you might like to try is putting an extra washer under the modulator.
This will hold it out from the box a little further and therefore reduce the neede seating pressure. Similar to what will happen when you using the adjustable modulator, but will cost about 10cents for the extra fibre washer.

Cheers for that additional info 1200coupe but its just too expensive.

Dodgeman I got a book that covers the same trans as yours 3N71B for $5 your right its a good book although it dosent tell were the markings to identify the trans Can anyone help with that?