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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Los_gatos on June 21, 2025, 12:27:39 AM

Title: In tank vent line size
Post by: Los_gatos on June 21, 2025, 12:27:39 AM
Searched as much as I could. What's the I.D. of the vent line (from the base of the pre pump strainer) inside the tank? Since this line has no pressure would another material work instead of SAE 30R10 rated line? Mine crumbled when I tried removed it. Thanks.
Title: Re: In tank vent line size
Post by: basketcasebiker on June 21, 2025, 12:50:39 AM
all fuel hoses are 5/16". any sort of rubber fuel hose should work fine. I'm not aware of any vent hose on the bottom of the strainer and I just replaced my pump
Title: Re: In tank vent line size
Post by: Laitch on June 21, 2025, 07:23:03 AM
any sort of rubber fuel hose should work fine
Only hose that can be submersed in fuel is suitable. Other types will degrade. SAE30R10 is high pressure fuel injection line; don't waste it on that application. MaxBMW's number is 16 13 1 455 350 for 1 meter of vent line @ eleven bucks plus shipping—enough left over to give as Halloween treats. You can probably find some locally but verify that it is fuel-submersible.
Title: Re: In tank vent line size
Post by: Laitch on June 21, 2025, 07:34:26 AM
There is a vent line on many of these basket-shaped filters—the earliest models may not have them. The vent was designed to evacuate air bubbles that form in fuel that is agitated when at a low level in the tank. Air bubbles entering the pump can damage it. The best prevention is don't try to run the Brick on a spits-worth of fuel and fumes.

My Brick's pre-filter had one of those lines when I first looked into the fuel tank 10,000 miles after I bought. It was attached to the basket port and the upper end was detached. Once I understood its purpose, I removed it. During the 70,000 miles of riding afterward, no problems have occurred; however, it's a thoughtful feature on BMW's part for riders that cannot pay attention to details.
 :laughing4-giggles:   
Title: Re: In tank vent line size
Post by: Los_gatos on June 21, 2025, 11:49:00 AM
Got off my lazy butt and measured for folks searching in the future. I.D. is 4mm and O.D. is 8mm. Thanks, basketcase and Liatch. I had seen your earlier posts about cavitation of the fuel pump.
Title: Re: In tank vent line size
Post by: frankenduck on June 22, 2025, 02:28:34 AM
Part number is 16131455350. You get a meter for only $11 from a dealer. You only need about 10.75" so the remainder can be used for other useful things like snorting coke or meth.
Title: Re: In tank vent line size
Post by: Laitch on June 22, 2025, 08:50:35 AM
You only need about 10.75" so the remainder can be used for other useful things like snorting coke or meth.
Or giving gerbils enemas.
Title: Re: In tank vent line size
Post by: frankenduck on June 23, 2025, 03:26:32 AM
Or giving gerbils enemas.

Why would a gerbil need an enema?

(Asking for a furry friend.)
Title: Re: In tank vent line size
Post by: Laitch on June 23, 2025, 08:42:46 AM
Why would a gerbil need an enema?
That is a question for the ages—21yrs or older.