Brake bleed question

[Supercharged111]

3. Same as yours

Same as my '00 Denali for that matter

Yeah, but on that b.a.s.t.a.r.d. year of a truck with no OBDII hole to plug into. . .

 

[Nad_Yvalhosert]

b.a.s.t.a.r.d. year of a truck

Ha!
I prefer "unicorn"

 

[delta_p]

If like to know how to ABS bleed a '95. 4 wheel ABS, but OBD1. Any suggestions?

Never worked with the 95. But I cycled through my tech2 for a 95, and it still shows a function test for each option 4 WAL 3 Sensor or RWAL. I assume it is the same test? but again I have never done it. Only my '96.

 

[Nad_Yvalhosert]

Never worked with the 95. But I cycled through my tech2 for a 95, and it still shows a function test for each option 4 WAL 3 Sensor or RWAL. I assume it is the same test? but again I have never done it. Only my '96.

I agree the function test would be the same, as the system is the same. The difference that roadblocks me is the lack of communication through the OBD1 DLC

 

[delta_p]

There is an OBD1 12 pin adapter came with the tech2 for DLC cable but the tech 2 has to be externally powered. Will it not communicate through the connector?

Here is a vetronix manual (pdf)

https://www.obd2be.com/download/gm-tech-2-user-manual.pdf

 

[Nad_Yvalhosert]

I dont have access to a tech 2

 

[Nad_Yvalhosert]

There is an OBD1 12 pin adapter came with the tech2 for DLC cable but the tech 2 has to be externally powered. Will it not communicate through the connector?

Here is a vetronix manual (pdf)

https://www.obd2be.com/download/gm-tech-2-user-manual.pdf

Thanks, I'll give that a read through, and I'll check with good Ole SnapOn. Maybe they have an adaptor for my Solus...

 

[Schurkey]

are you sure a tech 2 has a bleed function on a truck from this time?

Of course. That is, a REAL Tech 2. No promises on the Chinese clones.

I would think something like RABS has a bleed valve on the unit and just requires that done in a certain step compared to the rear drums, but that could be the f150 in my life bleeding into my gm side here

GM RWAL in the first few years had an iron body with a bleeder screw. After that, they had an aluminum body with no bleeder screw.

But RWAL is not the system used after '91. The '92--'94 C/K used EBC4 3-channel ABS instead of the one-channel RWAL. Other body styles used different ABS in different years.

'95 C/K began using EBC310 3-channel ABS module, far as I know that lasted until end of GMT400. At least, my '97 has EBC310.

Also if the rear lines were broken, id ask if these trucks have / use a residual pressure valve on the master cylidner outlet to the rear to maintain 10 ish PSI on the rear shoes so that when the brakes are applied the system doesnt have to overcome the springs before braking(thus starting to brake at the same time as the front)

Not that I know of. GM got rid of residual pressure valves in '71 or so; if they reintroduced them later, I don't know about it.

If like to know how to ABS bleed a '95. 4 wheel ABS, but OBD1. Any suggestions?

See .pdf attached. You'll need a scan tool. The Tech 2 works, so does various other scan tools. The GM instructions say you'll need a gallon of brake fluid--half-gallon before the ABS auto-bleed, and a half-gallon after.

HOWEVER, if you haven't bench-bled the master cylinder, that'll have to come first. And with a non-bench-bled master, that system is going to have massive air bubbles. Good luck.

I agree the function test would be the same, as the system is the same. The difference that roadblocks me is the lack of communication through the OBD1 DLC

If the ABS is able to communicate with a scan tool, OBD1 vs. OBD2 is no issue. The early RWAL from '87 would talk to a scan tool (sort of). The RWAL didn't have an auto-bleed that I know of, though. Later EBC4 and EBC310 absolutely talk to scan tools, although not all scan tools talk to ABS; or perform all the functions that the ABS module is capable of.

My Snap-On Solus Pro (8.2 software) won't do auto-bleed of the ABS module on my '97 (EBC310 module), although it'll do auto-bleed on my '03 Trailblazer. I can get speed sensor info, codes, and some other stuff with it--just no auto-bleed. Haven't tried it on anything other than the '03 TB. It may--or may not--auto bleed the EBC4 module.

The Solus Pro (14.2 software) WILL auto-bleed the '97, along with all the other ABS functions that the 8.2 will do.

 

[AuroraGirl]

Of course. That is, a REAL Tech 2. No promises on the Chinese clones.


GM RWAL in the first few years had an iron body with a bleeder screw. After that, they had an aluminum body with no bleeder screw.

But RWAL is not the system used after '91. The '92--'94 C/K used EBC4 3-channel ABS instead of the one-channel RWAL. Other body styles used different ABS in different years.

'95 C/K began using EBC310 3-channel ABS module, far as I know that lasted until end of GMT400. At least, my '97 has EBC310.

Not that I know of. GM got rid of residual pressure valves in '71 or so; if they reintroduced them later, I don't know about it.


See .pdf attached. You'll need a scan tool. The Tech 2 works, so does various other scan tools. The GM instructions say you'll need a gallon of brake fluid--half-gallon before the ABS auto-bleed, and a half-gallon after.

HOWEVER, if you haven't bench-bled the master cylinder, that'll have to come first. And with a non-bench-bled master, that system is going to have massive air bubbles. Good luck.


If the ABS is able to communicate with a scan tool, OBD1 vs. OBD2 is no issue. The early RWAL from '87 would talk to a scan tool (sort of). The RWAL didn't have an auto-bleed that I know of, though. Later EBC4 and EBC310 absolutely talk to scan tools, although not all scan tools talk to ABS; or perform all the functions that the ABS module is capable of.

My Snap-On Solus Pro (8.2 software) won't do auto-bleed of the ABS module on my '97 (EBC310 module), although it'll do auto-bleed on my '03 Trailblazer. I can get speed sensor info, codes, and some other stuff with it--just no auto-bleed. Haven't tried it on anything other than the '03 TB. It may--or may not--auto bleed the EBC4 module.

The Solus Pro (14.2 software) WILL auto-bleed the '97, along with all the other ABS functions that the 8.2 will do.

Not related on the truck thing specifically but people dont really get how important bleeding ABS units really is in all honesty, and I have never regretting getting my tech 2. its hard to stomach the cost for a clone but the amount of stuff its allowed me to do has been life changing. My 99 cars have Teves IV and Bosch 5.0 abs systems, and I would like to eventually get a 2000-2005 park avenue which would have a bosch 5.3(much better than bosch 5) and I know the Autel MK808 I have also would let me autobleed any of the 99 systems or the 2000s+

but for the guy with a 95, If I recall correctly, I had to use a ALDL plug in for my uncles 95 van despite the cars using a OBD2 plug. If im remembering that wrong, then whoops, I also seem to recall it not powering my tech 2 through that port and I had to use the cig lighter. but The functionality is very close to what obd 2 vehicles have its just the protocal is rarer and not supported by so many things. plus, technically, obd1 has nothing to do with the brake system since thats emissions and the brake system integration on the DLC sounds like it has been around on the trucks for a few years anywway, but of course 94-95-96 was special for both ford and GM with computer systems.

I have a 96 c1500 and a 96 f150. The f150 is actually hell because EEC-V from ford one year only on the inline 6 (300) on the OBS trucks.. unicorn parts!!! also ford so did not integrate anything to the DLC except OBD2 compliance lol. Everything else is all on its own. THat trucks RABS light comes on and then I go to read codes and code 16(all clear) so its like **** me then

 

[AuroraGirl]

There is an OBD1 12 pin adapter came with the tech2 for DLC cable but the tech 2 has to be externally powered. Will it not communicate through the connector?

Here is a vetronix manual (pdf)

https://www.obd2be.com/download/gm-tech-2-user-manual.pdf

The tech 2 has the 4or 5 connectors if you get it from a major clone source, the ones that are weird shaped are for Saab, Izuzu, stuff like there. The ALDL and the OBD2 port one are used a lot.
The cigarette lighter power cable or the 12 volt clips power cable had to be used iirc for a 95 and when you do that you run the power cable to the plug not the tech 2 itself
the tech 2 itself, you only power that I do believe if you are using it for function of indirectly using it to download calibrations by installing the stuff on the tech 2 and then bringing it to a vehicle. I think. Also for troubleshooting or playing with it not on a vehicle.

Also if you have a CANDI module attached youre wasting space take that off lol