[HHGadget]

I've read somewhere the vacuum pump can be retrofitted. These pumps are (most of them) made by the same German company, Hella (yes the famous headlight brand). In fact when my mother's Volvo burned the pump (due to a faulty vacuum switch the pump ran nonstop) we replaced it with one out of a Cruze. Exactly the same, Hella model UP28 but now mom's "Ford" Volvo has a GM branded part

After fitting and wiring the pump you flash a new calibration to your BCM or ECM (don't remember which one) and voila you have positive braking all the time.

This is on my to-do list, but other forum members have mentioned it can be a daunting task. I have a tech 2 clone and have been pondering the do-ability of this “upgrade”.

 

[HHGadget]

In heavy but highway speed traffic i have been in boost when a non attentive driver merges right in front of me causing my foot to instantly swith from throttle to brake.
Brake pedal stuttered towards the floor.
Very disconcerting.

 

[HHGadget]

In heavy but highway speed traffic i have been in boost when a non attentive driver merges right in front of me causing my foot to instantly swith from throttle to brake.
Brake pedal stuttered towards the floor.
Very disconcerting.

Not had the driveway issue as i also always let her idle for a few minutes before moving.

 

[HHGadget]

Both before and after.
Definitely more noticeable after though.

 

[HHGadget]

I have had to go from wide open throttle to full brakes only once or twice. I am ever so happy that it is not the regular occurence that it seems to be for you.

Yes. LA has some of the worst drivers.
Its a huge, densely populated, sprawling area and there is a scary mix of young aggressive drivers, older overly cautious drivers, a healthy amount of distracted (phone) drivers and a large dollop of poor folk, without insurance mixing it up on the freeways and surface streets. It can be chaotic, head on a swivel driving even for a simple grocery store run.
A block away from me two people died when some kids in a brand new Vette ran a red light and t-boned a woman on her way to work at 5 in the morning. There was very little left of either car, or three of the storefronts he plowed into.
This type of thing happens pretty regularly around here.
So yes, unfortunately i find the sudden braking is unfortunately common.

if its not the missing vacuum pump, what could cause that?

 

[HHGadget]

The brake ladders to the floor like jerk jerk jerk downwards while the ABS is engaging in this one circumstance.
It is not always repeatable but when it does happen it is at highway speeds.

I can repeat getting the ABS to engage but it doesn't suddenly zipper down to the floor.
Maybe i should look into the ABS cavitation procedure.
Not sure where it is in the menu tree on the Tech2 clone though.

Is the procedure itself outlined in the manuals?

 

[HHGadget]

This is the thread

'08 Brake Issue: The Correct Fix | Saturn Sky Forum (skyroadster.com) '08 Brake Issue: The Correct Fix | Saturn Sky Forum (skyroadster.com)

View attachment 129045

Appreciate the thorough reply Rob.
The brakes do function but when this happens each “bump” of the ABS drops the pedal to the floor much faster and lower to rhe floor than the normal ABS does.
The few times (2 or 3 times over the course of daily driving in the last couple of years) it has alway been a scenario where i am accelerating to pass and somebody merges unannounced in front of me and i instinctively jump to the nrake pedal hard.
I have tried to reproduce it “at will” and have not been able to do so.

 

[HHGadget]

I have the same (early 08) setup, but with the TSB applied. I also have NEVER had any braking issue - even at cold startup. @HHGadget I have a feeling there's something else wrong with your brakes.

Well shoot, going have to take it to a shop then.
Thanks for all the feedback guys

 

[HHGadget]

LOL You are of course correct. Plus it has 8 cylinders sucking on the vacuum system.

One could argue the V8 “mod” is a vacuum pump on ones wallet.

 

[HHGadget]

I am not familiar with his big brake upgrade, but if it uses bigger bore calipers it going to take more fluid to move the piston the same distance, so the ABS should cause the pedal travel to be more pronounced

Bill

This is very interesting. I wonder if the ABS system can be calibrated via the Tech2 Clone?

 

[HHGadget]

Diagnosis so far:
1) No leaking fluid anywhere in the system.
2) Brakes work great, stopping power is strong with the only issue being when this happens.
3) Very hard to re-create the symptoms at will. Again I tried today and everything seems solid. That being said i live in the city and it can be difficult to find an area where it is safe to be at speed and then slam the brakes...
4) Brake fluid is less than a year old.
5) Brake calipers and lines are less than a year old.
6) No codes being thrown, pending or otherwise related to the braking system.
7) Dash ABS dummy light lights up on firt start as it should (i.e. it is working)
8) During braking the car does not pull in any one direction. (I.e. as it should)
9) Parking brake works great.

-I am going to bleed the brakes again as a basic first step. Will report back to this thread on that.
-I am going to see if I can find the Tech2 menu for ABS Cavitation and try that out. I will report those findings here.

 

[HHGadget]

FWIW I found this set of instructions online. Not sure if they are "genuine" instructions but....

Solstice L4-2.0L Turbo (2008)

Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > Antilock Brake System Automated Bleed Procedure

Brake Bleeding: Service and Repair
Antilock Brake System Automated Bleed Procedure

Antilock Brake System Automated Bleed Procedure
Caution: Refer to Brake Fluid Irritant Caution (See: Service Precautions/Technician Safety Information/Brake Fluid Irritant Caution) .

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice (See: Service Precautions/Vehicle Damage Warnings/Brake Fluid
Effects on Paint and Electrical Components Notice) .

Important: Before performing the ABS Automated Bleed Procedure, first perform a manual or pressure bleed of the base brake system. Refer
to Hydraulic Brake System Bleeding (Manual) (See: )Hydraulic Brake System Bleeding (Pressure) (See: ) . The automated bleed procedure is
recommended when one of the following conditions exist:

*

Base brake system bleeding does not achieve the desired pedal height or feel

*

Extreme loss of brake fluid has occurred

*

Air ingestion is suspected in the secondary circuits of the brake modulator assembly

The ABS Automated Bleed Procedure uses a scan tool to cycle the system solenoid valves and run the pump in order to purge any air from the secondary
circuits. These circuits are normally closed off, and are only opened during system initialization at vehicle start up and during ABS operation. The
automated bleed procedure opens these secondary circuits and allows any air trapped in these circuits to flow out toward the brake corners.

Performing the Automated Bleed Procedure

Notice: The Auto Bleed Procedure may be terminated at any time during the process by pressing the EXIT button. No further Scan Tool prompts
pertaining to the Auto Bleed procedure will be given. After exiting the bleed procedure, relieve bleed pressure and disconnect bleed equipment per
manufacturers instructions. Failure to properly relieve pressure may result in spilled brake fluid causing damage to components and painted
surfaces.

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle (See: Maintenance/Vehicle Lifting/Service and Repair) .
2. Remove all four tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation (See: Maintenance/Wheels and Tires/Service and

Repair) .

3. Inspect the brake system for leaks and visual damage. Refer to Symptoms - Hydraulic Brakes (See: Hydraulic System/Testing and

Inspection/Symptom Related Diagnostic Procedures/Symptoms - Hydraulic Brakes) . Repair or replace components as needed.

4. Lower the vehicle.
5. Inspect the battery state of charge. Refer to Battery Inspection/Test (Solstice) (See: Starting and Charging/Testing and Inspection/Component

Tests and General Diagnostics/Battery Inspection/Test)Battery Inspection/Test (SKY) (See: Starting and Charging/Testing and
Inspection/Component Tests and General Diagnostics/Battery Inspection/Test) .

6. Install a scan tool.
7. Turn the ignition ON, with the engine OFF.
8. With the scan tool, establish communications with the ABS system. Select Special Functions. Select Automated Bleed from the Special Functions

menu.

9. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle (See: Maintenance/Vehicle Lifting/Service and Repair) .

10. Following the directions given on the scan tool, pressure bleed the base brake system. Refer to Hydraulic Brake System Bleeding (Manual) (See:

)Hydraulic Brake System Bleeding (Pressure) (See: ) .

11. Follow the scan tool directions until the desired brake pedal height is achieved.
12. If the bleed procedure is aborted, a malfunction exists. Perform the following steps before resuming the bleed procedure:

*

If a DTC is detected, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions) , and diagnose the appropriate DTC.

*

If the brake pedal feels spongy, perform the conventional brake bleed procedure again. Refer to Hydraulic Brake System Bleeding (Manual) (
See: )Hydraulic Brake System Bleeding (Pressure) (See: ) .

13. When the desired pedal height is achieved, press the brake pedal to inspect for firmness.
14. Lower the vehicle.
15. Remove the scan tool.
16. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation (See: Maintenance/Wheels and Tires/Service and Repair)

.

17. Inspect the brake fluid level. Refer to Master Cylinder Reservoir Filling (See: Hydraulic System/Brake Master Cylinder/Service and

Repair/Procedures/Master Cylinder Reservoir Filling) .

18. Road test the vehicle while inspecting that the pedal remains high and firm.

 

[HHGadget]

New bit of data. Had an opportunity yesterday to actually repeatedly run hard and attempt to activate the ABS a couple times in a row.
First time it sank like i have been describing.
Second time it seemed to sink but with more stopping power.
The third time was the same as the second except, the bump, bump, bump of the ABS continued after i released the pedal for about two bumps.
maybe this is normal and i just didnt notice it before? Regardless the car stopped well all three times and the brake pedal felt and operated normally afterwards.
weird?

 

[HHGadget]

Ok bled the brakes normal style one tiny bubble drivers side.
Then foe round two i used the Tech 2 ABS procedure = that produced many bubbles.
ABS bleed procedure for the win!

 

[HHGadget]

Took it for a quick loop around the block (not a real test) and they certainly seemed to grab better and faster with less sinking than before.
Will post a higher speed test result when i get a chance.
So far it seems an improvement.

 

[HHGadget]

When i did my brake swap last year there was some mention of not needing to do this procedure. After this experience i recommend it as it was relatively quick and did indeed get bubbles out that a regular bleed did not.
Keep in mind my system was almost completely dry when i started as i replaced the calipers, brake lines and master cylinder for whatever that is worth…

 

[HHGadget]

Since I can't figure out how to start a conversation on this, going to ask here and hope HHGadget sees this.
I'm coming from over on the sky roadster forum, just bought a used 2007 saturn sky not too long ago. I just replaced the calipers, rotors, pads, and lines and have bleed the system twice now and it still feels like there is air in the system. I'm really hoping the automated bleed will help.
Since you've already done this, what exactly is involved? I have the tech2win reader and software so am ok there. Did all 4 wheels have to be off at the same time? My work area is limited and it's a bit of a pain to put the car up on 4 jack stands here. The service manual does say lift and remove all four wheels, and some lifting and lowering, but other than that just says to follow the instructions in the scan tool.
Thanks for any info you could provide!

-Dave
2007 Saturn Sky 2.4L Manual

The nice thing about the tech2 is the ABS bleed procedure. It will step you through each wheel as part of the procedure.
I do recommend having all four wheels off to speed it up, but i remember it is not so automated that you have to run around the car as it does each wheel.
So theoretically you could remove one or two wheels at a time, but if you can do all four, why not?

 

[HHGadget]

I should add i had bled my brakes probably 4 times by the time i got around to trying the tech2 ABS. Sure enough some micro bubbles came out.