Brake accumulator squeak help

[Reedern21]

Hey there everyone i have a few questions on the abs pump/ Brake Booster / Accumulator squeakbafter pump engages. From what i understand this is a fairly common issue with this pump/ master cylinder. I dont actually have a Gs300 so mine may be slightly different (crownmajesta). What im wondering ia if there is anyway to even temp fix this issue as i need to have a vehicle inspection and they failed it previously due to the brake warning indicator light coming on. Even if anyone knows of a way to avoid having the light come on so i can deal with this issue at a later date. They failed it based on the indicator light alonebas the inspection check sheet says the hydraulic system passed and all other braking components passed. Any suggestions would be greatly appreciated. Please point my in the right direction if i have misposted this.