I don't have a check valve on brake booster hose. Will it affect braking?
 

I installed piece of rubber hose

Am guessing it will throw a code and wouldn't be any different that driving with an original piece that is leaking.Just curious, why did you do that instead of buying a new piece? They aren't that expensive and are easy enough to get.

5 min $3 solution is better than $30 and 5 days.

Meh

I have some pad tape, bailing wire and a pair of pliers for your future repairs.

Good one Dell. My feelings also.
Now to give a serious answer to your question. If you ever find yourself at highway speed 65/70/75 and need to make a quick breaking to prevent a bad situation you will find the engine is not producing enough vacuum to assist breaking. Vacuum exists at low throttle and diminishes as RPM rises and stabilizes.
Order the right part and prevent injury to yourself or worse to someone else.

Thanks!
I can probably find check valve in NAPA store. Or ebay.
https://www.ebay.com/sch/i.html?_fro...valve&_sacat=0

Post 17=

https://www.jaguarforums.com/forum/x...-start-213476/

Thanks! I believed other cars don't have check valves. Probably they all do.

Many do, Mercedes, BMW, Porsche, Lexus, etc =

Many vehicles employ a vacuum brake booster in order to provide additional power to the braking system. It's designed to provide consistent flow of hydraulic brake fluid to the brake master cylinder while increasing brake pressure and helping heavy vehicles stop more easily. This component is common on a variety of consumer cars, trucks and SUVs. From time to time, the vacuum brake booster is susceptible to damage or typical wear and tear. This includes the brake booster check valve. The check valve is designed to suck out air that is trapped in the brake booster without letting additional air enter the cylinder. This protects the brake lines from developing an air bubble which can seriously impact braking performance. This part connects the body of the brake booster to the vacuum hose and is a safety solution that still allows the brakes to work – even if the engine is shut off.

I installed Mercedes check valve, braking feels better. I didn't think it was bad before but it feels better now.
Thanks for suggesting.