Problem with Brake Cutoff Sensor Killing Power (Zeegr F1 Pro)

[CoffeeandBikes]

I was riding yesterday far and away. I was going up a steep dirt road and all motor power stopped. There were no error codes. I checked the connections and all was well connected. I discovered that if I quickly pulled and let go of the left (front) brake lever I would temporarily have power. I eventually made it home in this manner. It appears that there is a problem with the brake cutoff sensor for the left brake. When this happens the brake light is illuminated. If I engage the left brake lever and release it so it snaps back the light will go off and power will resume. I also tested disconnecting the sensor wire and the bike runs without problems (but no brake light from front brake or cutoff.)

Here is a highlighted image of the nut securing the sensor wire. There is no locking mechanism - no screw or anything. All I can do is loosen that wire nut by unscrewing. When I do that I can wiggle it and the brake light will go off. I did not find a "sweet spot", and there appears to be no way to tighten that nut in different positions. These are cheapy Logan hydraulic disc brakes that came with my Zeegr F1 Pro. Does anyone have suggestions to fix this?

 

[HumanPerson]

New ebike brake lever and some of ther crush washers you'll need to reconnect the hydraulic line then bleed and add more fluid.

 

[CoffeeandBikes]

New ebike brake lever and some of ther crush washers you'll need to reconnect the hydraulic line then bleed and add more fluid.

It seems to be the sensor itself. If I loosen that barrel nut that I highlighted in yellow and slightly adjust the depth the cutoff will disengage. The problem is the "sweet spot" is very small and there's no way to lock it into that position. I doubt it should be that sensitive. Are you saying that problems with air in the hydraulic line can cause the sensor to act up like this?

 

[HumanPerson]

It seems to be the sensor itself. If I loosen that barrel nut that I highlighted in yellow and slightly adjust the depth the cutoff will disengage. The problem is the "sweet spot" is very small and there's no way to lock it into that position. I doubt it should be that sensitive. Are you saying that problems with air in the hydraulic line can cause the sensor to act up like this?

It could be that the little pressure sensor in that barrel nut assembly thing might be going bad.

Oh no, i didnt meant anything bout air in the lines i meant if you change the whole brake lever assembly you'll need to bleed the brakes.

Those little sensors do some wonky things when they get ready do stop working.

 

[CoffeeandBikes]

It could be that the little preassure sensor in that barrel nut assembly thing might be going bad.

Oh no, i didnt meant anything bout air in the lines i meant if you change the whole brake lever assmebly you'll need to bleed the brakes.

Those little sensors do some wonky things when they get ready do stop working.

There's around 500 miles on the bike, but I do use the brakes a lot. I have a message into the seller. I think the warranty is one year. I'll update when/if they respond. Thanks!

 

[Fritz Katzenjammer]

Air in the brake system. It’s limiting the piston’s movement, preventing proper return. Time for a bleed.

I get this right out of the box on at least 10% of the bikes I build. During Covid, when the factories in the orient were having problems with staffing, I got shipments of bikes where everything required some tinkering on at least one brake to get things working properly.

 

[Annieolnie]

There's around 500 miles on the bike, but I do use the brakes a lot. I have a message into the seller. I think the warranty is one year. I'll update when/if they respond. Thanks!

See if they will just send you a new sensor. Logan does have a repair video.

 

[CoffeeandBikes]

See if they will just send you a new sensor. Logan does have a repair video.
View attachment 21239

Thank you much. You're so very helpful!

 

[DieselTech]

Try adjusting the brake sensor or get a new brake sensor.

I had this happen to me, I then adjusted the brake sensor & all good now.

 

[CoffeeandBikes]

Try adjusting the brake sensor or get a new brake sensor.

I had this happen to me, I then adjusted the brake sensor & all good now.

This particular one doesn't have a set screw. It just screws in. I did back out the barrel nut to adjust the sensor position to see when the brake light would go off. It is a very, very small sweet spot and didn't seem consistent. I'll probably have to replace it. I'm waiting to hear back from the seller. Thanks!

 

[rontaki]

Censorship is never good!

 

[CoffeeandBikes]

UPDATE: Seller said they are sending a new sensor.

 

[CoffeeandBikes]

UPDATE 8/25/25 - I finally received the replacement brake sensor! The seller actually sent 2 new sensors and a new wrench! Swapped out the old one and everything works fine now. I went riding the other day with the front brake sensor disconnected. I had a couple WHOAAA moments when that automatic cruise control didn't turn off after applying the front brake  With this automatic cruise control brake cutoffs are ESSENTIAL!

 

[Teos]

Hello I could use some help- I had a fall this morning on my Zeegr F1 and afterwards I notice my right brake lever had a crack and it feels slack and there's a noticeable tiny bit that may have fallen off , but its working, the brake light turns on, indicator turns on. but the electric function is not working(including throttle) the LCD has an E5 error. Help a lady please I've attached a picture of the crack

 

[Annieolnie]

Hello I could use some help- I had a fall this morning on my Zeegr F1 and afterwards I notice my right brake lever had a crack and it feels slack and there's a noticeable tiny bit that may have fallen off , but its working, the brake light turns on, indicator turns on. but the electric function is not working(including throttle) the LCD has an E5 error. Help a lady please I've attached a picture of the crack

Well, I think you came to the right thread. The E5 error is your brake cut-off switch but it sounds like you may need a whole new brake lever. I believe you have Logan 2 piston brakes for ebikes. You can unplug the cut-off on the right side to see if that ends the error, just remember you now only have a left cut-off switch. See if doing that brings back your throttle. You can get a new lever with switch or a whole new right side brake if that is easier. You just have to have the caliper compatible with your frame bracket on the rear wheel and your cut off plug needs to match the one you have. There are Logan levers on Google but I don't know what is easiest for you to order. Perhaps CoffeeandBikes can tell you where he sourced his parts, but he is far, far away from England. Did you buy the ebike from a British dealer?

 

[Teos]

Well, I think you came to the right thread. The E5 error is your brake cut-off switch but it sounds like you may need a whole new brake lever. I believe you have Logan 2 piston brakes for ebikes. You can unplug the cut-off on the right side to see if that ends the error, just remember you now only have a left cut-off switch. See if doing that brings back your throttle. You can get a new lever with switch or a whole new right side brake if that is easier. You just have to have the caliper compatible with your frame bracket on the rear wheel and your cut off plug needs to match the one you have. There are Logan levers on Google but I don't know what is easiest for you to order. Perhaps CoffeeandBikes can tell you where he sourced his parts, but he is far, far away from England. Did you buy the ebike from a British dealer?

Thank you for your response. i may have to order a new right side. When I unplug the cut off on the right side to see it shows error for a while and then shows the normal screen, when I try to throttle, it does sometimes and doesn't at other time. I've attached all the error screen I've gotten. I've also attached a picture of the brake lever on my bike and the one I've seen on Aliexpress, would that fit a replacement? Thank you

 

[Annieolnie]

What sort of throttle do they let you have in the UK? Do you have short burst throttle, to a certain low mile per hr. or is it a full throttle for "off road"? That brake lever looks correct. It is a 2 pin red male on the lever, yes? I know Aliexpress does have some that are marked Logan. We have such absolute idiocy going on with the tariffs right now that a lot of Chinese websites won't even currently open for us, so it is hard for me to track things down and of course, some of the prices are laughable. Your throttle looks a bit unique. Maybe CoffeeandBikes can tell me if it is familiar. He has the US version of your bike.

 

[Teos]

Yeah, in the UK they only let us have a short-burst throttle that works up to about 15km/h. Anything more than that and the bike stops being classed as an e-bike and turns into a moped in the eyes of the law, So it’s not like the full throttle you guys get in the US. But mine is a proper throttle goes 25/30km/h. Thank you for helping out. I'll order and watch videos on how to fix it, if you've any video I can watch ill appreciate it.

 

[Annieolnie]

I just lost a piece of my post. So, I think I have found your throttle. A funny thing about throttles, if you can match the plug and you can completely match the exact pattern and style of the grips, it is usually correct. Grin Technologies in Canada appears to have your throttle. They are good people and some of the smartest in the business, so you can double check with them, and give them your model number, but I think I'm correct. Throttles break often and if you have crashed and now it is glitchy, you will probably have to either completely rewire it, or buy a new one.

 

[Annieolnie]

I've never had to replace just a lever on a hydraulic ebike brake, I've replaced the whole side. I will look around. You will definitely need to drain that sides tube to change it out, so you will need a refill and bleed kit for that. Aliexpress is by far the cheapest. I'll post the one I have here. Syd and Macky on YouTube are very friendly and go over different ways to bleed your brakes. I will look and see if Park Tools has any tutorials on changing a lever.