I've had my 08 Yukon in the shop since the 14th for brake issues. My brakes would just suddenly not work. Work just fine one minute and the next time I would get in the truck, brake pedal to the floor. I took it to the shop and they replaced one part for a $1000 that didn't fix it. Told me I need another part for another $2000. The biggest problem with this is they haven't been able to find one. Not one .... Anywhere ... What in the world did I get myself into? A vehicle that looses it's brakes and no parts to fix it. Unbelievable GM !

 

what part did they replace?

 

They replaced the brake master cylinder. Had a small (very small) leak in the body.

 

Is there anything in the braking system that is a hybrid specific part?

Quite weird there are no parts available.

 

The brake modulator valve is the hybrid specific part that they can't seem to find. Basically is a electric motor driven pump that builds up the brake pressure. It's not used on the regular vehicles.

 

I am having this same exact issue right now. Car has been in shop for 3 weeks, same brake system described. They replaced my Master Cylinder, brakes did the same thing the next day. Today they tell me they are searching for a used part as they cannot get a new one. They are telling me the same exact part. Brake Modulator Valve.

 

I understand your pain... My truck went into the dealership on the 14th of May. They replaced the Master Cylinder because it had a small leak from the seam. Of course it didn't fix it. I told them back in Feb when I first took it in for this problem that I thought it was the Modulator Valve based on the noise(s) I would hear coming from the valve. Now I'm over two months waiting on the part. The dealership searched for a new one through GM channels and then started contacting salvage yards to try to find one. They didn't have any luck doing that either. Then they told me that the manufacturer (TRW) is fabricating some new parts and that they were expected to ship on July 14. Well, so far the follow up calls with the dealership have been that they can't get any further info from the manufacturer yet if the parts did indeed ship. SO FRUSTRATED with GM !!! My dealership has been helpful but without the part they can't fix it.

 

Good news finally! The dealership called me back late this afternoon and said that the shipment of modulators came in today and they will ship one out to my dealership for Thu delivery. Maybe finally I'll have my Yukon back.

 

Glad to hear you're going to be back on the road soon.

Very troubling to hear that GM has allowed spare parts to reach *zero* before taking any corrective action.

 

Can you take pics of this so called modulator?