SwerveMonkey's Street Goblin #197 - 08 Donor

[SwerveMonkey]

Posting from dictation on mobile

Distance from front of straight edge to center tunnel is 32 and 3/4 for both wheels

Toe plate measurements
Front tow plate is 68 and 3/4
Rear tow plate is 68 and 1/8

Split the difference and you got 5/16

Attempting it to get 1/8 toe in

Edit.
New toe plate measurements
Front tow plate is 68 and 1/4 rear toe plate is 68 and 1/2

 

[SwerveMonkey]

Evened up forward straight edge measurement to 32 and 1/2 each

Toe plate measurements
Front plate 68 and a half rear plate 68 and 3/8

Edit ...
measuring before jamming bolts
front plate 68 and 1/8
Rear plate 68 and 3/8

 

[Rttoys]

So 1/4” toe in? Should be fine

 

[Joebob]

When using 2 tape measures, I would check that they both give the same measurement near your 68" measurement range, or switch places and retake measurements to confirm.

 

[SwerveMonkey]

with the rear alignment complete, i took it out for a test to check reaction and drive characteristics.
found that the brakes are being activated just enough to drag and cause the brake lights to enable.
i thought it may have been the booster misaligned but it looks ok and straight
I have no doubt that the brake system isn't leaking since the drag is present.

I am suspicious of the location of the brake pedal pin since I am going from Non-SS to SS, the lengths are likely different and the pedal may require modification or replacement.

 

[Ross]

I had a brake dragging issue because of a misalignment from the brake caliper to the brake pedal.

 

[SwerveMonkey]

Yupe! I went searching and found that post as well & that was one of the first things that I went to check.
I also double checked the emergency handbrake being too taught... Neither of these things have been the smoking gun though.

I'm also noticing that the brake lights stay lit even though the brakes switch is in the correct position fully retracted

Although I have the brake pedal disconnected from the booster...I'm still having the brake lights come on... This is probably separate from the brakes dragging
But should be noted as I did convert from early model booster to late model, so the shaft distance is might be different

 

[Joebob]

loosen the nut and bolt that holds on the sensor to allow a little bit of wiggle. If I tightened mine down, it would shift the sensor into thinking that the brakes were engaged. 1/2-3/4 turn loose and now lights the brakes only when push on pedal. You can use a nylock nut to keep from vibrating loose.

Joe

 

[TravMac]

You might want to pull the master cylinder off of the brake booster and check the pin that actually actuates your brakes. I actually had mine doing something similar because i bolted it down too hard without any sort of backstop to the booster. The pin was giving a constant hold on my brakes!

 

[SwerveMonkey]

Ok. So problem solved ... The problem was not surprisingly between the steering wheel and the seat. LoL.

So I forgot that the calipers are required to be reset after the work that was done. I never thought to reseat the pads and push back the calipers. Rewinding the rear Solstice calipers was also a new experience. Used a pair of needle nose pliers to do the job. Next time I think I'll actually buy the tool that makes the job that much easier.

On a side note, I had a thought that maybe I should also do a transmission flush oddly enough finding out that the manual transmission takes automatic transmission fluid?

 

[comegetjoe]

*edit - Swerve and Ross did the research and have the correct answer above and below.

 

[Ross]

Here is the oil specification for Chevrolet >> 2008 >> Cobalt L4-2.2L
Getrag 5 Speed - Manual Transmission
Dextron VI(R) US P/N 88861003

It does say ATF on the container!

 

[SwerveMonkey]

OK,so... further updates show that problem persists where something is slowing the car down.

I've already did a flush and fill for the Transmission, the drained fluid looked somewhat dark and not a lot of metallic shimmer, maybe a good sign.

Having did the flush and driven it around the block gently the dragging persisted. I'm not sure if that is from the tranny fluid not permeating fast enough or if somehow i did something wrong <shrug>... but i followed the Chilton's to the T, ha ha.

anyway, after talking with a few folks there may have been something i might have overlooked. adjusting the master cylinder or the power booster to tune it for the application.

Another theory is that it may be due to my Frankenstein Brake system, because I did not track what trim model each piece was from.
I doubt this... but it would not be too crazy that for whatever reason I am drawing too much vacuum from the intake to the booster.
I'll take time to test a drive around the block WITHOUT the vacuum connection on the booster to see.
but again, i have my doubts, but it would be a good test to see what the booster delete is like.

 

[Gtstorey]

Have you tried pushing the car on level ground? I don't think chasing issues with the brake booster will get you anywhere. Without reading back over your build log, I can't think of anything you could do to drastically change vacuum, and even if you did, it shouldn't make the brakes drag. And if the brakes are dragging much you should be able to smell them. Have you tried checking the brake temps after coasting to a stop?

 

[SwerveMonkey]

did not think to check brake temps after coasting.... my brain has been turned mush recently by my job, ha ha.
will give this a shot once i have time to take it out for a test drive.

just as a request for a sanity check.... it shouldn't matter if the Non-SS booster is mated with an SS cylinder right??
I have an unhealthy habit of overthinking things and chasing red herrings.
I know some master cylinders have adjustability but i thought the Cobalt's setup was plug-&-play.

 

[Gtstorey]

It's not impossible that a mismatch on the booster and master cylinder is causing problems. If the piston is not returning all of the way to the resting position because of interference with the booster, it won't bleed pressure off correctly.

 

[SwerveMonkey]

a couple STLs for headlight mounting... lost previous model of what is currently mounted.
The problem with the current draft is that the headlights interfere with opening the front bonnet.
at the moment, the headlights have to swivel out of the way to access the front opening swing.

wanted to put these here as a sort of repository before sharing in the main 3d printing thread.

 

[D&dgoblin69]

Swerve do you have a floor jack so you can lift wheels off the ground to see if the front or rear wheels are locked up? I had an issue where my booster was preloading the master cylinder causing brakes to drag. I lossen the nuts on the master cylinder till brakes freed up. The master cylinder sits deep into booster so it didn’t cause a vacuum leak. If you back master cylinder out of booster you can check for vacuum leaks with a piece of hose while cars running put hose to ear and place around master to booster connection if no hissing aka booster leak then your golden.

 

[SwerveMonkey]

I think the issue is resolved at this point... simply ran to the local pick-your-part and grabbed a matching cylinder and booster.
I would say that the theories about the cylinder being sticking too far into the booster are probably correct.... I did try and isolate the wheels but the condition of dragging brakes would not show up with it on jack-stands as opposed to running.

I still have the suspicions that i mixed and matched parts incorrectly and that is why the brake system was not only dysfunctional, but also different for the master cylinder fittings.... the previous SS cylinder had different sizes than the Non-SS... both the original donor and the junkyard pair i found recently were Non-SS and shared identical fittings for the master cylinder.

 

[ah.b.normal]

I think the issue is resolved at this point... simply ran to the local pick-your-part and grabbed a matching cylinder and booster.
I would say that the theories about the cylinder being sticking too far into the booster are probably correct.... I did try and isolate the wheels but the condition of dragging brakes would not show up with it on jack-stands as opposed to running.

I still have the suspicions that i mixed and matched parts incorrectly and that is why the brake system was not only dysfunctional, but also different for the master cylinder fittings.... the previous SS cylinder had different sizes than the Non-SS... both the original donor and the junkyard pair i found recently were Non-SS and shared identical fittings for the master cylinder.

What was the donor for these bits? Year and Trim level?