My son has been driving our 2000 Q45 at college in Tempe, AZ. He reported that the brake pedal has become very hard to push. I had him take the Q to a local Brakes Plus store. The store went over the brake system for quite a while and diagnosed a failed brake booster. The store recommends that the master cylinder be changed along with the booster and that the system receive a bleeding.

I read a thread here on changing the booster and it does not sound like a fun job laying on one's back under the steering wheel. So I may have a shop do this one.

My questions:

The OEM booster is no longer made. As far as I can tell, I think I am stuck using a Cardone reman with part number 538211. I found this one at Summit Racing for $150.

https://www.summitracing.com/parts/aaz- ... /year/2000

Any better suggestions for how to source a replacement part?

Conventional wisdom says to replace the master cylinder along with the booster, according to the brake shop. Do I need to do this? The OEM master cylinder is no longer available either. I can find a new version of a non-OEM part, but is that going to be any better than just putting the OEM part back on?

The shop says the rest of the brake system is fine and my son is safe to drive the car while using a bit of extra muscle to operate the brakes. Any disagreement here on that thought?

The brake booster thread that I read here says that the OEM booster seldom fails. My son said they went over the car for quite a while to confirm a failed booster. Any concern that the shop has misdiagnosed the problem?

I could potentially tackle this job myself, but I am out of town on an RV trip with my wife and won't be back for 6 weeks. So I am trying to coach my son through the process of getting this fixed. Thanks for any help.

There's no conventional wisdom that connects a failed booster to the MC unless the system is losing brake fluid and you find the missing fluid inside the booster. Otherwise, they don't have the slightest thing in common besides the pushrod and bolts connecting them. That part is pretty much baloney.

Ok. Good info on the booster and master cylinder connection. We will focus on getting just the booster replaced.

Amayama.com can still get most original factory Nissan parts for our Q45s from Japan, though they're not cheap nor quick to ship.

Thanks, but I ordered the Cardone reman unit from Summit Racing this morning.

Know you found your part, but just to add to this: I had gotten mine from autozone couple years ago reman. Somehow, these will be out of stock, and then reappear in stock. Went that route and change the cylinder just as precaution.

Don’t go with a used one though unless doing it yourself. Someone sold me one on eBay, it didn’t have much a vacuum (according to tech) and had to pay labor twice.

We went with the Cardone reman from Summit Racing, which was much cheaper that Auto Zone or O'Reilly for the same reman. We brought the bleeder and the shop did the install and brake bleed for what I thought was a good price ($250). My son, who drives the Q, said the pedal is so firm that it feels like he barely has to push on it.