除轉彎外，挖掘機其他部件運轉正常。維修挖掘機起動復合繼電器的中點信號端有電源電壓（檢查中點信號端信號的輸入是否與電源有短路現象或起動機中點輸出不正常）。修理挖掘機若起動復合繼電器輸出正常，則檢查起動復合繼電器輸出端到起動機之間的線束連接是否完好（測量起動機端的起動線是否有電壓）；若以上情況完全正常，可以判斷為起動機不能正常工作。挖掘機維修左右轉(zhuan)(zhuan)向(xiang)指示燈(deng)工作(zuo)(zuo)不正(zheng)常(chang) 當手柄開(kai)關撥到(dao)左轉(zhuan)(zhuan)或(huo)右轉(zhuan)(zhuan)時，挖掘機(ji)左右轉(zhuan)(zhuan)向(xiang)燈(deng)不閃爍。請檢(jian)查左、右轉(zhuan)(zhuan)向(xiang)燈(deng)與(yu)閃光繼電(dian)(dian)器(qi)負載端之(zhi)間(jian)的(de)線(xian)束。由于主泵和自減壓閥(fa)(fa)是挖掘機(ji)液壓部分的(de)常(chang)用部件(jian)(jian)，說明(ming)主泵和自減壓閥(fa)(fa)之(zhi)間(jian)沒有故障。在旋轉(zhuan)(zhuan)電(dian)(dian)磁閥(fa)(fa)的(de)控制油(you)(you)路出(chu)口，三通連(lian)接一個量程為4兆(zhao)帕的(de)壓力表(biao)(biao)，操作(zuo)(zuo)挖掘機(ji)旋轉(zhuan)(zhuan)。結果表(biao)(biao)明(ming)，這里的(de)壓力僅為0。1兆(zhao)帕，這表(biao)(biao)明(ming)釋放制動(dong)(dong)器(qi)的(de)油(you)(you)壓過低，無(wu)法釋放制動(dong)(dong)器(qi)，從而(er)使挖掘機(ji)無(wu)法旋轉(zhuan)(zhuan)。拆(chai)卸(xie)旋轉(zhuan)(zhuan)鎖電(dian)(dian)磁閥(fa)(fa)時發現閥(fa)(fa)芯卡(ka)住，取出(chu)閥(fa)(fa)芯時發現里面有一個小的(de)破O型圈。清洗(xi)所有部件(jian)(jian)，重(zhong)新安裝并測試機(ji)器(qi)，轉(zhuan)(zhuan)動(dong)(dong)動(dong)(dong)作(zuo)(zuo)將恢復(fu)正(zheng)常(chang)，并故障排除。

     挖掘機回(hui)(hui)(hui)(hui)轉(zhuan)(zhuan)系統操作活動(dong)(dong)結束，操作控制(zhi)手柄已處于中位時(shi)(shi)，挖掘機在(zai)慣(guan)性力(li)的作用(yong)下回(hui)(hui)(hui)(hui)轉(zhuan)(zhuan)角偏大，無法直接停(ting)在(zai)一個預定目(mu)標位置。據分析，這種象是企(qi)業由(you)于資金回(hui)(hui)(hui)(hui)轉(zhuan)(zhuan)制(zhi)動(dong)(dong)能(neng)力(li)不(bu)(bu)及時(shi)(shi)或(huo)制(zhi)動(dong)(dong)力(li)技術不(bu)(bu)足問題造成(cheng)的，它(ta)與我們解除制(zhi)動(dong)(dong)的油壓大小(xiao)及回(hui)(hui)(hui)(hui)轉(zhuan)(zhuan)鎖(suo)定磁閥(fa)、回(hui)(hui)(hui)(hui)轉(zhuan)(zhuan)制(zhi)動(dong)(dong)片和制(zhi)動(dong)(dong)過(guo)(guo)程(cheng)中密封(feng)等零(ling)部件(jian)(jian)公(gong)司(si)有(you)(you)關。在(zai)檢查汽車制(zhi)動(dong)(dong)回(hui)(hui)(hui)(hui)油路時(shi)(shi)發現，在(zai)回(hui)(hui)(hui)(hui)油路的節流(liu)孔(kong)處有(you)(you)一膠質顆粒物，節流(liu)孔(kong)雖(sui)沒有(you)(you)得到完全被堵死，但已導(dao)致回(hui)(hui)(hui)(hui)油過(guo)(guo)慢，使得整個制(zhi)動(dong)(dong)管理部分主要起作用(yong)的時(shi)(shi)間可以推遲，因此使上部回(hui)(hui)(hui)(hui)轉(zhuan)(zhuan)停(ting)止時(shi)(shi)滑移量(liang)過(guo)(guo)大。清洗各元件(jian)(jian)發展特別是對于節流(liu)孔(kong)及細(xi)小(xiao)油道。安裝各元件(jian)(jian)后(hou)試(shi)機時(shi)(shi)，回(hui)(hui)(hui)(hui)轉(zhuan)(zhuan)滑移量(liang)已在(zai)相關規(gui)定的范(fan)圍內，故障分析排除。