SwerveMonkey's Street Goblin #197 - 08 Donor


Well-Known Member
Old hubs from the donor with XXX,XXX miles on them? "Hello Rockauto, I'd like to place an order..." :D
That's exactly what i am thinking now... initially i considered scrounging through my left over donor bolts, but realized that was a DEATHLY bad idea.
found a few options... most expensive but convenient would be local AdvancedAuto... cheapest so far is 1A parts @ ~ 60 each.


Well-Known Member
while i am too lazy to go grab my chilton... i googled torque specs for the wheel hubs.
came across this link for the L61 engine code... titled "L61 Ecotec - Overview, Torque, Fluid, and Engine Specs"
as well as this link for the LSJ engine code... titled "Ecotec 2.0L LSJ Power + Torque Specs"

though neither have what i am looking for... suppose I will have to rummage around the garage for that manual


Well-Known Member
While still hoping to form a sort of spring maintenance list i found a very spongy brake pedal.

I went ahead and bleed the lines, albeit in an EXTREMELY rudimentary way, by using a precision cut in a water bottle to collect fluid as the pedal was pushed, ha ha.
However, bleeding the lines served no help and in the wake of testing and inspections i noticed a rather gushy noise coming from what i thought was the Master Cylinder.... more likely the brake booster upon closer inspection.

after some time & research to better understand the scenario, i figured upgrades were in order...
If I had to replace the master cylinder, why not find something (if possible) better than OEM.
Moreover, if i had to replace the MC why not see if there are any upgraded brake systems that work better for the goblin.

I found the thread from JSATX's conversion and am going to go a similar route, since as he pointed out "if [JSTAX] was going to drain all the brake fluid anyway now was the time to make the switch."
thread for reference : http://dfkitcar.com/forum/index.php?threads/manual-brake-conversion.1038/

now it is a matter of getting more info on what options there are, how others fared on their choices, & making a B.O.M. to have the local CFO review ha ha ha.


Well-Known Member
Check for brake fluid in the brake booster and replace the booster if there’s fluid in it
I was puzzled why after bleeding the brakes i still had a spongy pedal and found something in good ol' youtube university about brake boosters failing... and yeah, i checked with a zip tie dip stick, LoL. it came back up with about an inch of fluid on it....

just from looking online for the last hour or so I am thinking that the booster delete route might not be the most beneficial for me... but then again I'm trying to convince myself that it is worth while to opt for the most reliable and safe option for the type of driving and where i will be driving it.

at this point considering the local in which i will be driving it might be... might be, better to have the booster than to not have it.
there does not seem to be a middle ground for this particular section of the brake system...
to paint a slippery slope : either have the booster and risk lock up, OR swap to MC only with proportioning and not have the stopping power in an instant for emergencies... still looking for some sort of middle ground if it exist.

hmm, could be a good reason to make another video for the youtube channel, LoL


Goblin Guru
I recommend adding the proportioning valve first. I also added a vacuum regulator so I can adjust how much boost the brakes get.
I don't know why it never crossed my mind to look for something like that! Neat! If I could have just a hint of assist that would be great. I actually like running manual brakes, but doing 100+ at the strip it seems a bit unsafe lol


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If you opt to stick with the donor setup - and you find the booster is the issue - I have a functional donor brake booster that I will not be using. :)
I definitely wont overlook this offer! Thank you. I'll DM you to coordinate, I'd like to pay for the shipping.
As it turns out the booster does have more fluid in it than just in the vacuum chamber...
I was playing around with it and heard sloshing even though i drained the firewall side.
pressed the piston and got more liquid flowing from there.


Well-Known Member
I recommend adding the proportioning valve first. I also added a vacuum regulator so I can adjust how much boost the brakes get.
THIS! yeah, it crossed my mind recently when trying to better understand how the brake booster fails and what to look for.
I wasn't sure it would make that much of a difference, but it is definitely worth giving a shot after having seen others using the same tactic to tune the force of the booster.

I'm still trying to find a way to bench test the master cylinder I have on hand in case it can be salvaged... I'm sure it can be rebuilt, gotta believe it can be. most videos i find are for motorcycles, same principal really, but barely anything for the dual piston setup in the cobalt.


Goblin Guru
Master cylinder rebuild kits used to be common, don’t know if they are now. Rebuilding them depends on whether the cylinder is damaged, usually with pitting. Again, you used to be able to get hones and oversized seals, but probably hard to come by now.
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Well-Known Member
OK... so ... spent some time this week removing rust from rear "steering rack" and found that tie rod ends have lost a bit of grease. I'm not entirely worried since the stability of them are not at critical, but I will be replacing the tie rod ends soon since it would be an improvement.

Got the brake booster sent over from Desert Sasqwatch and it didn't fit the Master Cylinder.
It seems that becasue we may have had different different Donor trims there are different brake boosters models.
I am going to assume because I had a NoN-SS trim model.
My original brake booster was different than what is more commonly used as a donor... the SS trim.

[ In my worst caribbean accent ] So... Mi bredren who haf' di ess ess, who ah' dem tink dah boosta betta on dah ess ess
If the booster and cylinder are hands down "better" on the SS trim than the Non-SS... it might be worth it to swap to an SS cylinder.

at this point I am either going to house the sent over booster until another builder (SS-trim) needs it...
or simply swap out the master cylinder for one that matches the model trim that Sasqwatch sent me...

Goblineers, thoughts??

EDIT: going to swap to SS trim cylinder.... thankfully the purchase can be returned and I can look to grab a cylinder that matches the brake booster that D.S. sent over.... still open to thoughts and suggestions : )
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