ghettocruiser

iTrader: (4)

Ok that was a long title. Just figured Ide show you all how I did my rear brake lines. The rear is a Strange 12-bolt for a 4th gen car. The car had 4 channel ABS on it...so I had to come up with a way to make it a single hose in the back. Ill get the part number for you guys if anyone wants it. Its a inexpensive hose from Autozone. It accepts a 1/4" line with double flare for the inlet, and two 3/16" line double flares for the caliper lines. I was able to use the stock hard lines. Just had to tweak the ends a bit, and of course cut them and flare them with new fittings. Really easy, really clean, and the hose is long enough that I should be able to drop the axle to its limits without stretching it too bad. I plan to put some zip ties around the hose where it gets close to touching, just to act as a rub gaurd. I dont expect it to touch ever though. Here is a pic... Sorry if this is common sense stuff, but Im trying to post pictures of things that I couldnt find by searching...to try to help out some others.





The bracket that holds the inlet side of the brake hose seemed a bit long. So I trimmed it up a bit. The hose that I got was pretty long, and doing this helped it to fit better. I made sure that when I cut it, I left enough material to make that little nipple that goes into the hole and keeps it it from spinning. Worked great.





Finally...Im not sure if anyone else has done this. Im using the 4th gen plastic gas tank. And I watned to keep the lines and wiring as clean as possible. So along with the 4th gen fuel lines, I also used the 4th gen wiring bulkhead. I basically just made the 3rd gen hole a bit bigger, and rivited the thing in place wtih some RTV to keep the H2O out. After deleting the ABS wires from teh bulk head, I ran them up under the carpet to the front. Clean, simple, plug and play.




Let me know if you have any ?'s or if you want some more pics. So far its coming together pretty smooth. Im workin out some kinks in the 4th gen body harness to try to make things even more plug and play. Thats about all that worries me right now is wiring.

Justin

ghettocruiser

iTrader: (4)

Just realized that this isnt exactly engine swap related... Well I guess the gas tank wiring part is... Just figured this to be the best place for any LS1 specific stuff. If it needs to be moved feel free...

Justin

88FormulaKiller

iTrader: (8)

hey man, i just did the same exact thing over the weekend and never saw this thread but heres a question for ya, the wires coming out of the bulkhead on the Inside of the car, which ones get spliced into my 3 Original wires running up to the front of the car? (originally a TBI/T5) In my bulk head i plugged in the larger plug and the lower plug but i dont know which 3 from the LS1 side get spliced into my original 3 wires from the tank (just re-wording what i just asked i guess)

camarotucker

iTrader: (2)

"Wiring change, cut the 3rd gen pigtail as close to the sender as possible where it goes into the tank, 3 pins. Locate the 4th gen pigtail where it goes into the sender and cut a few inches free. There are 6 pins, 4 are reused

4th gen pigtail, 6 pin
Pin B is fuel pump 12v, splice this direct from the 3rd gen harness gry to gry

Pins C blk and D blk/wht are grds for the pump and sender respectively. Splice these to the 3rd gen grd wire blk

Pin A ppl is fuel level sender signal. Splice this to the last wire on the 3rd gen pigtail ppl to ppl

Pop the new sender in, splice 4 wires, done

Harness still functions like before"

from Pocket

camarotucker

iTrader: (2)

The above reference is for replacing the fourth gen fuel level sender with the Grand Prix sender (part numer in another thread)to retain stock gauges and making the connection from the fourth gen tank to the thirdgen harness. Gettocruiser showed another option which is to use the fourth gen harness and run it to the front of the car. What ever route you choose the above post will at least give you the pinouts.

88FormulaKiller

iTrader: (8)

thanks, thats exactly what i was looking for

five7kid

iTrader: (14)

Since you referenced sizes in inch fractions, I assume the hose is SAE rather than metric. I forget if it was '84 or '85 that started the metric fittings, but either way it causes me heartburn because my 82's have SAE lines and all the later better factory brake stuff is metric.

iansane

iTrader: (1)

I realize this thread is a bit old but what about the thirdgen style brake hose would make it not work?

ghettocruiser

iTrader: (4)

Thanks for helping guys! I dont know much about tank wiring because I just used everything from the 4th gen. Even the bulkhead connector. So I didnt re-pin or do any wiring with that really.

As for why the stock thirdgen line wouldnt work...

You know...I cant remember for sure. Part of the reason was needing a simple way to mount it to my 12 bolt. From my time spent with the Jeeps, I knew there were some hoses that existed with a mount hole that would work perfect. They usually are held down by the axle vent that screws in.

Also, I made a new brake line from the front to rear, and I was double flaring it with SAE and using common hardware. So I wanted to find a line that was SAE, long, and simple. The lines on the axle are stock LS1...but since I did some custom bending, I re-flared them and added my SAE hardware.

It basically stemmed from me wanting a new brake hose, having to adapt for the 12 bolt, and wanting something simple and clean that would work for me. And I found it basically by digging through Autozone's brake hose boxes haha. Again..mostly from my Jeep experience I was able to remember some part numbers to get me started.

J.

88FormulaKiller

iTrader: (8)

so in reference to the 4 wires posted above spliced into the 3rd gen harness (using a grand prix level sender) splicing the ppl 4th gen (from a 4th gen sender) into the 3rd gens ppl sender wire to gauge doesnt work?? or so it would seem since mine is not working...

camarotucker

iTrader: (2)

It should work. The fourth gen sender has two grounds which splice into the single thirdgen ground. One of these grounds is dedicated to the fuel level circuit, double check that the wires are connected correctly.

88FormulaKiller

iTrader: (8)

still trying to resolve this.... i put it aside and used the trip to track my gas but ive had it, i modded my 3rd gen fuel gauge with resistors and hooked my wires correctly, so i think, still no correct reading, pegged at full.... J what are the wires twisted together for? i also have like 4 gray wires (thin ones, from the 4th gen harness side...? a pink one? a white wire and brown wire twisted together?? a green one?) i cant find a wiring diagram for the life of me....

88 350 tpi formula

iTrader: (9)

im lost as to why you even did this. 4 channel originally or not you could have kept the stock replacement thirdgen hose using bubble flare (metric) fittings and lines.


other person with the 82, use metric prefabbed lines on the later brakes and go to SAE nuts and double flare the lines at the hose..

camarotucker

iTrader: (2)

When Gettocruiser made this thread he was pioneering the swap, all the information we have now, he didnt have.

88Formulakiller, I am confused what set up you have. If I understand, you have an LS1 plastic tank, and you are using the fourth gen harness from the tank and running it to the front then splicing it in at the gauges. You are trying to use resistors to modify the gauges to read the fourth gen fuel sending unit?

Here is some more info,

https://www.thirdgen.org/forums/ltx-...s1-fuel-2.html

88FormulaKiller

iTrader: (8)

yes thats correct, im not puttin an 0-90 sender, the 33-270 is more accurate. im just putting the tank back in now, the float wasnt stuck, i now believe the gauge may be toast. im not sure yet, im going to buy another cluster and mod the fuel gauge again incase 12v made its way to the fuel gauge and fried it. 750 L98 has a thread on how to modify the gauge.

ghettocruiser

iTrader: (4)

My reasons for doing this...the hose install anyway, was because everything was set up for 4 channel ABS. Nothing that attached to the axle for the dual brake hoses was set up how I wanted it to be. I wanted a single line from the front to back, to a single hose, to two hard lines on the axle.

I also never liked bubble flares, or metric haha. So I just converted it all to double flare SAE. The only metric lines/fittings are at my master cylinder, and they are converted at both the adjustable prop valve and the line lock for the front. From there back its all good old SAE double flares.

As for the tank wiring... That is a bit far back for me to remember. I think a lot of the gray wires were for EVAP... I think. Pretty sure the sender wire was purple?

Im not of much help on the gauge mods either, because I quickly switched to a programmable gauge and avoided all of the hassle. You guys running stock clusters obviously want to avoid this.

Sorry I cant help ya much on the wiring! I avoided a lot of the headaches by using as much of the thirdgen stuff as possible, and skipping some of the work by going aftermarket gauges.

Good luck fellas!

J.

camarotucker

iTrader: (2)

I see two reasons for modifiying the gauge with resistors. The first one is that the resistors are cheaper than buying the sender. However, the chances of damaging the gauge during the mod and having to buy a repalcement in the process could make it close in cost as going with the new sender route. The second is a guy who wants to retain the stock gauges as well as the fourth gen emisions. Iircc the PCM uses the signal from the sender to operate the purge. I know the fourth gen sender is more accurate, however, when operating below half a tank you run the risk of fuel pump getting hot and burning out.

camarotucker

iTrader: (2)

With that being said, here is how I did mine. I cut the filler neck off the thirdgen tank with a sawzall. This way I could pull the tank out without having to remove the rear end. I then spliced the fourth gen fuel sender harness into the thirgen harness using the pinouts in post #4. I made my splice on the thirgen harness about 6" back on the plug that goes into the floor pan above the third member. This way you can use the thirdgen harness from the floor pan bulkhead forward as well as unplug the harness later if needed for maintenace. Keep in mind that my swap did not retain emissions. I paid $110 for the Grand Prix (you get 2 in the box) sender and split the cost with another board member brining the cost to $65. Install details in link in post #14.

88Formulakiller, you could run the fourth gen harness as far as you want towards the front and splice in wherever within the circuit, it is just more work. I saw you said that there was a thread where some figured out how to make the resistors work. To date I have not heard of one board member who has successfully got the resitors to work. Either the gauge reads wrong, or not at all (burned up). Im sure it can be done, but I would rather have some one else figure out exactly how to do it before I did. That way they can eat the cost of the experiment and not me.

88FormulaKiller

iTrader: (8)

the mod with the resistors has been done and works correctly, heres the thread

https://www.thirdgen.org/forums/ltx-...auge-40-a.html

saturday i dropped the tank, float wasnt stuck, hooked up pump/sender outside tank, moved sweep to half, no change at gauge, im thinking i might have fried the gauge first time around when i used .5 watt resistors instead of 1 or 2 watt. ill buy another gauge and try again. it just stays pegged at full. i may go buy a potentiometer and double check gauge again before hand, just losing my patience with it.

BuiltZ28

*bump*

Does anyone know the part number for that rubber hose?